0654_w23_qp

Question 1:

Topic – B16.3 Monohybrid inheritance

(a) Fig. 1.1 is a pedigree diagram for the inheritance of a genetic condition called cystic fibrosis.
The allele for cystic fibrosis is recessive a.
The allele for no cystic fibrosis is dominant A.

(i) Use Fig. 1.1 to state:
the number of people with the genotype aa ………………………
the number of people with the sex chromosomes XY. ………………………

(ii) State the term that is used to describe the genotype aa.

…………………………………………………………………………………………………………………….

(iii) The couple labelled P and Q in Fig. 1.1 decide to have another child.
Complete the genetic diagram in Fig. 1.2 to calculate the percentage likelihood of this child having cystic fibrosis.

percentage likelihood of child having cystic fibrosis. ………………………

Fig. 1.2

(b) Cystic fibrosis causes mucus produced by cells lining the airways to become very thick and sticky.
(i) State the name of the cells in the airways that produce mucus.

…………………………………………………………………………………………………………………………
(ii) Explain why people with cystic fibrosis are more likely to have frequent lung infections.
………………………………………………………………………………………………………………………….
………………………………………………………………………………………………………………………….
………………………………………………………………………………………………………………………….
(c) Lung cancer is another disease that affects the lungs.
State the major cause of lung cancer.
……………………………………………………………………………………………………………………………

▶️Answer/Explanation

Ans: 1(a)(i) 2 ;
4 ;

1(a)(ii) homozygous recessive ;

1(a)(iii)

parent genotype correct ;
offspring genotype correct ;
25 (%) ;

1(b)(i) goblet (cells) ;
1(b)(ii) mucus traps, pathogens / bacteria ;
cilia unable to remove (thick) mucus ;

1(c) (tobacco) smoking ;

Question 2:

Topic – C11.3 Fuels

Crude oil contains hydrocarbon molecules.
(a) State what is meant by a hydrocarbon.
…………………………………………………………………………………………………………………………..
…………………………………………………………………………………………………………………………..
(b) Alkanes are hydrocarbon molecules.
(i) State the type of bond found in alkane molecules.
Tick (√) one box.

(ii) Alkanes are saturated hydrocarbons.
State which molecule is a saturated hydrocarbon.
Tick (√) one box.

(c) Larger alkanes are cracked to form smaller alkanes and another type of hydrocarbon molecule.
(i) State the name of this other type of hydrocarbon molecule.

…………………………………………………………………………………………………………………….

(ii) State the conditions needed for cracking.

1 ……………………………………………………………………………………………………………………….
2 ……………………………………………………………………………………………………………………….

(iii) The equation shows the cracking of C$_{24}$H$_{50}$.
Balance the equation.
C$_{24}$H$_{50}$ → C$_{10}$H$_{22}$ + ………….. C$_{6}$H$_{12}$ + …………..

(d) Hydrocarbon molecules are used as fuels.
Burning fuels produce pollutants in the air. These pollutants cause problems.
Draw one line from each pollutant to the problem it causes.

▶️Answer/Explanation

Ans: 2(a) (compound that) contains only carbon and hydrogen (atoms) ;
2(b)(i) single covalent ;
2(b)(ii) C$_{3}$H$_{8}$ ;
2(c)(i) alkene ;
2(c)(ii) high temperature ;
catalyst ;

2(c)(iii) $ C_{24}H_{50}\rightarrow C_{10}H_{22}+ 2 C_{6}H_{12} + C_{2}H_{4}$
correct number of C in products ;
correct number of H in products ;

2(d)

correct link for carbon monoxide ;
correct link for sulfur dioxide ;

Question 3:

Topic – P1.6 Energy, work and power

Nuclear power stations use nuclear fission to generate electricity.
The nuclear fission of uranium releases thermal energy.
The thermal energy produced is used to convert water into steam which drives the turbines that
generate electricity.
(a) State one advantage of generating electricity from nuclear fission.
…………………………………………………………………………………………………………………………..
…………………………………………………………………………………………………………………………..
(b) Barium-141 ($_{56}^{141}\textrm{Ba}$) is produced by the nuclear fission of uranium.

Barium-141 decays by emitting a beta-particle.
(i) Use the correct nuclide notation to show the decay of barium-141.

$_{56}^{141}\textrm{Ba}\rightarrow _{…….}^{……}\textrm{La}+_{……}^{……}\textrm{}\beta $

(ii) A 160g sample of barium-141 has a half-life of 18 minutes.
Calculate the time it will take for the mass of barium-141 in the sample to decrease to 10g.

time = ……………………………………. minutes

(i) The high-pressure steam is at a pressure of 1.8 × 10$^{7}$Pa.
Blade A has a surface area of 0.12m$^{2}$.
Show that the force acting on blade A is 2.2 × 10$^{6}$N.

(ii) The moment of the force, from the high-pressure steam acting on blade A, is 1.35 × 10$^{6}$Nm.
Calculate the distance d, from the centre of blade A to the pivot of the turbine.

distance d = …………………………………………….. m
(iii) When the turbine spins, blade A moves with a constant speed but a changing velocity.
Explain why the velocity of blade A changes.

…………………………………………………………………………………………………………………..

……………………………………………………………………………………………………………………

▶️Answer/Explanation

Ans: 3(a) any one from:
does not release, greenhouse gases / CO$_{2}$ ;
does not contribute to, global warming / climate change ;

3(b)(i) $_{56}^{141}\textrm{Ba}\rightarrow _{57}^{141}\textrm{La}+ _{-1}^{0} {\beta }$

La correct ;
β correct ;

3(b)(ii) use of 4 half lives ;
(4 × 18 =) 72 (minutes) ;

3(c)(i) 1.8 × 10$^{7}$ × 0.12 ;
3(c)(ii) (d =) m ÷ f / (d =) 1.35 × 10$^{6}$ ÷ 2.2 ×10$^{6}$;

(d =) 0.61 or 0.63 (m) ;

3(c)(iii) the direction (of blade A) changes;

Question 4:

Topic – B12.1 Respiration

(a) A student investigates the effect of different types of sugar on the anaerobic respiration in yeast.
She mixes yeast with five different types of sugar solutions of the same concentration and
measures the volume of gas produced after 2 hours.
Table 4.1 shows the results.

(i) Identify the sugar in Table 4.1 that produces the largest volume of gas.

…………………………………………………………………………………………………………………….

(ii) Calculate the rate of anaerobic respiration for sugar A in Table 4.1.

rate of anaerobic respiration for sugar A = ……………………………………. cm$^{3}$/min

(iii) State the name of the gas produced in this investigation.

……………………………………………………………………………………………………………………

(iv) State one practical use for the anaerobic respiration of yeast.

……………………………………………………………………………………………………………………

(b) Describe three ways that aerobic respiration is different from anaerobic respiration in humans.
1 …………………………………………………………………………………………………………………..
……………………………………………………………………………………………………………………..
2 ………………………………………………………………………………………………………………….
…………………………………………………………………………………………………………………….
3 ………………………………………………………………………………………………………………….
…………………………………………………………………………………………………………………….

(c) Respiration is one of the characteristics of living organisms.
State one other characteristic.
……………………………………………………………………………………………………………………..

▶️Answer/Explanation

Ans: 4(a)(i) C ;
4(a)(ii) evidence of unit conversion / (2 hours =) 120 minutes ;

0.075 (cm$^{3}$ /min) ;

4(a)(iii) carbon dioxide ;
4(a)(iv) bread making / named practical use of anaerobic respiration by yeast ;
4(b) any three from:
requires oxygen ;
(releases) more energy (per glucose molecule) ;
produces carbon dioxide ;
produces water ;
does not produce lactic acid ;

4(c) any one from:
movement ;
sensitivity ;
growth ;
reproduction ;
excretion ;
nutrition ;

Question 5:

Topic – C7.1 The characteristic properties of acids and bases

(a) The pH of a solution describes how acidic or alkaline it is.
State which of these values shows the pH of a strong acid.
Tick ( √) one box.

(b) Complete the sentences about dilute hydrochloric acid and aqueous sodium hydroxide.
Choose words from the list. Each word may be used once, more than once or not at all.

acceptor catalyst donor an electron a proton

Dilute hydrochloric acid is defined as an acid because it is ……………… ……………… .
Aqueous sodium hydroxide is defined as a base because it is ……………… ……………… .

(c) (i) Hydrochloric acid, HCl, reacts with copper carbonate, CuCO$_{3}$.
Copper chloride, CuCl$_{2}$, water and carbon dioxide are made.
Construct the balanced symbol equation for this reaction.

…………………………………………………………………………………………………………………….

(ii) Describe the test for carbon dioxide and its positive result.

test ………………………………………………………………………………………………………………
positive result ……………………………………………………………………………………………….

(d) 2.45g of sulfuric acid reacts with 1.60g of copper oxide.
Copper sulfate, CuSO$_{4}$, is made.

H$_{2}$SO$_{4}$ + CuO→ CuSO$_{4}$ + H$_{2}$O

Calculate the number of moles of sulfuric acid and the number of moles of copper oxide.
Use your answers to determine the limiting reactant in this reaction.
Show your working.

limiting reactant = ……………………………………..

▶️Answer/Explanation

Ans: 5(a) 1 ;
5(b) proton donor
proton acceptor
;;

5(c)(i) 2HCl + CuCO$_{3}$ → CuCl$_{2}$ + H$_{2}$O + CO$_{2}$
formulae ;
balancing ;

5(c)(ii) test: limewater ;

observation: milky/cloudy / white precipitate ;

5(d) relative formula mass of H$_{2}$SO$_{4}$ = 98 and of CuO = 80 ;
moles of sulfuric acid (2.45 $\div$ 98 =) 0.025 ;
moles of copper oxide (1.60 $\div$ 80 =) 0.02 ;
(there are less moles of copper oxide so) copper oxide is the limiting reactant ;

Question 6:

Topic – B15.3 Sexual reproduction in plants

Fig. 6.1 shows a bee collecting pollen from a flower.

(a) The maximum speed of a bee is 5.8 m / s.
(i) Calculate the maximum distance a bee can travel in 60 seconds.

maximum distance = ……………………………. m

(ii) The mass of the bee is 0.20 g.
Calculate the kinetic energy of the bee when it is moving at 5.8 m/s.

kinetic energy = ………………………… J

(b) The flower uses brightly coloured petals to attract the bee. The petals reflect ultraviolet light
and visible light, both of which are part of the electromagnetic spectrum.
State one similarity and one difference between visible light and ultraviolet light.
similarity ………………………………………………………………………………………………………………….
…………………………………………………………………………………………………………………………………
difference ………………………………………………………………………………………………………………….
…………………………………………………………………………………………………………………………………

(c) The bee becomes positively charged as it flies through the air.
Suggest how this charge is produced.
…………………………………………………………………………………………………………………………………
…………………………………………………………………………………………………………………………………
…………………………………………………………………………………………………………………………………
(d) When suspended in water, the pollen from the flower can be used to study Brownian motion.
Describe how Brownian motion provides evidence for the kinetic molecular model of matter.
…………………………………………………………………………………………………………………………………
…………………………………………………………………………………………………………………………………
…………………………………………………………………………………………………………………………………

▶️Answer/Explanation

Ans: 6(a)(i) (d =) v × t/(d =) 5.8 × 60 ;
348 or 350 (m) ;

6(a)(ii) conversion: (0.20 g =) 0.00020kg ;

(KE =) 1⁄2 mv$^{2}$/1⁄2 × 0.00020 × 5.8$^{2}$ ;
(KE =) 0.0034 or 3.4 × 10$^{-3}$ (J) ;

6(b) similarity: travel at speed of light / transverse waves ;
difference: (visible light has lower) frequency / (visible light has longer) wavelength / ORA ;

6(c) friction (with air) ;
(negative) electrons (move) ;
(electrons move) off (surface of) bee ;

6(d) random motion (of pollen grains / particles) ;
caused by collisions with water / molecules / other particles ;
(movement because of idea of) fast(er) moving small(er) particles ;

Question 7:

Topic – B5.1 Enzymes

(a) A scientist measures the activity of the enzyme amylase at different temperatures.
Fig. 7.1 shows a graph of the results.

Complete the sentences to describe and explain the results in Fig. 7.1.
Amylase breaks down the substrate ………………………. into smaller molecules of ………………………. .
As temperature increases, the activity of amylase increases until it reaches its optimum
temperature of ………………………………. °C.
As the temperature increases, the amylase particles gain …………………………………………. energy.
This results in more frequent successful collisions between amylase and its substrate.
At temperatures above 75°C, all of the amylase has become …………………………………………. .
This means the …………………………………………. of amylase has changed shape and is no
longer complementary to the substrate.

(b) State two parts of the alimentary canal which secrete amylase.
1 ………………………………………………………………………………………………………………………………
2 ………………………………………………………………………………………………………………………………

…………………………………………………………………………………………………………………………………
…………………………………………………………………………………………………………………………………

(ii) State the name of the chemical test for the presence of proteins.

………………………………………………………………………………………………………………………………….

▶️Answer/Explanation

Ans: 7(a) starch ;
simpler sugars ;
25 ;
kinetic ;
denatured ;
active site ;

7(b) any two from:
salivary glands ;
pancreas ;
small intestine ;

7(c)(i) carbon
hydrogen
oxygen
nitrogen
;;
four correct = 2 marks
two or three correct = 1 mark

7(c)(ii) biuret ;

Question 8:

Topic – C2.5 Simple molecules and covalent bonds

Non-metallic elements exist as simple molecules with covalent bonds.
Non-metallic elements can also exist as giant covalent structures.
(a) Oxygen is a simple molecule with covalent bonds.
Table 8.1 gives some properties of four substances, A, B, C and D.

State the most likely set of properties for oxygen.
Choose from A, B, C or D.

answer …………………………………………………

(b) (i) Iron reacts with oxygen to make hydrated iron oxide (rust).
4Fe + 3O$_{2}$ + 6H$_{2}$O 4Fe(OH)$_{3}$
224g of oxygen reacts with iron to make 1kg of rust.
Calculate the volume occupied by 224g of oxygen gas.
The molar gas volume at room temperature and pressure is 24dm3.

volume of oxygen gas = ………………………………………….. dm$^{3}$

(ii) Chromium is added to iron to form the alloy stainless steel.
Describe how the properties of iron are changed by adding chromium.

…………………………………………………………………………………………………………….
…………………………………………………………………………………………………………….

(c) Ammonia, NH$_{3}$, is also a simple molecule with covalent bonds.
Complete the dot-and-cross diagram in Fig. 8.1 to show the covalent bonding in ammonia.
Only show the outer shell electrons.

(d) Graphite and diamond are giant covalent structures.
Fig. 8.2 shows the structures of graphite and diamond.

Explain why graphite is used as an electrical conductor but diamond is not.
Use ideas about structure and bonding.
…………………………………………………………………………………………………………………………………
…………………………………………………………………………………………………………………………………
…………………………………………………………………………………………………………………………………

▶️Answer/Explanation

Ans: 8(a) D ;
8(b)(i) Mr of O$_{2}$ = 32 ;
moles of O$_{2}$ = 7 ;
volume of O$_{2}$ (7 × 24) = 168 dm$^{3}$ ;

8(b)(ii) any one from:

(stainless steel) does not rust / rusts more slowly ;
(stainless steel) is stronger / harder / tougher ;
change in malleability ;

8(c)

one covalent bond between N and H correct ;
rest of structure correct ;

8(d) each carbon atom bonds to 3 other carbon atoms ;
delocalised / free electrons ;
(electrons) move ;
or
in diamond each carbon atom bonds to 4 other carbon atoms ;
diamond does not have delocalised / free electrons ;
(electrons) cannot move / (electrons) held in covalent bonds ;

Question 9:

Topic – P3.3 Electromagnetic spectrum

A student is investigating electromagnetic induction by dropping a magnet through a coil of wire.
The coil of wire is connected to a device which measures the electromotive force (e.m.f.) induced in the coil.
Fig. 9.1 shows the equipment used by the student.

(a) Fig. 9.2 shows the induced electromotive force (e.m.f.) measured as the magnet falls through the coil of wire.
Fig. 9.2 shows two peaks, X and Y.

(i) Explain why:
peak X is positive and peak Y is negative

………………………………………………………………………………………………………………………….
………………………………………………………………………………………………………………………….

peak Y has a larger magnitude than peak X.

(ii) The data in Fig. 9.2 was obtained using a coil made of 800 turns of wire.
On Fig. 9.2, sketch the data which would be obtained if a coil containing 400 turns was used with the same magnet.

(b) When writing up the results, the student is not sure whether to write about the induced
potential difference or the induced electromotive force (e.m.f.).
Place ticks in Table 9.1 against each statement that is correct for potential difference and for electromotive force (e.m.f.).
You may place one or two ticks in each row. The first row has been done for you.

(c) The coil of wire used in the investigation is made of copper. Copper is a solid.
Complete the sentences to describe the arrangement of atoms in a solid and the properties of a solid.
In a solid, the arrangement of atoms is ……………………… .
The forces between atoms are ……………………… which allows the atoms to ………………………
but keeps them in a ……………………… position.

(d) Copper is a good thermal conductor.
Describe how thermal energy is transferred in copper.
…………………………………………………………………………………………………………………………………
…………………………………………………………………………………………………………………………………
…………………………………………………………………………………………………………………………………

▶️Answer/Explanation

Ans: 9(a)(i) (peak X is positive and peak Y is negative)

S causes peak (X) and N causes peak (Y) (as it passes through coil) ;
(peak Y has a larger magnitude than X)
(idea that) the magnet is increasing in velocity / speed ;

9(a)(ii)

same shape graph drawn with line crossing x-axis at same point ;
both peaks lower than original ;

9(b)

9(c) regular / ordered / a lattice
strong
vibrate
fixed ;;
four correct = 2 marks
two or three correct = 1 mark

9(d) atoms vibrate ;
(idea that) vibrations passed on to next atom ;
(idea of) transfer by (free) electrons ;

Question 10:

Topic – B19.1 Habitat destruction

Fig. 10.1 shows aerial photographs of the same area taken at different times.
Photograph A was taken in 1985.
Photograph B was taken in 2000.
Areas of forest are darker in the photograph and areas that have been cleared of trees are lighter.

(a) The change shown in Fig. 10.1, between 1985 and 2000, affected the environment.
(i) Explain why this change affected the concentration of carbon dioxide in the atmosphere.
………………………………………………………………………………………………………………………….
………………………………………………………………………………………………………………………….

(ii) Describe the effects of this change on animal species in the area.

………………………………………………………………………………………………………………………….
………………………………………………………………………………………………………………………….
(b) The area in Fig. 10.1 can be described as an ecosystem.
Define the term ecosystem.
…………………………………………………………………………………………………………………………
………………………………………………………………………………………………………………………..
(c) State the principal source of energy input into the ecosystem.
………………………………………………………………………………………………………………………..
(d) Asexual reproduction can be useful to plants in the wild.
State two advantages of asexual reproduction.
1 ……………………………………………………………………………………………………………………..
……………………………………………………………………………………………………………………….
2 …………………………………………………………………………………………………………………….
……………………………………………………………………………………………………………………….

▶️Answer/Explanation

Ans: 10(a)(i) (fewer trees so) less photosynthesis ;

less carbon dioxide removed (by trees) / more carbon dioxide in atmosphere ;

10(a)(ii) any three from:
extinction ;
migration ;
habitat / shelter / breeding grounds, destroyed ;
food sources removed ;
food chains / food webs, disrupted / affected ;

10(b) (a unit) containing (all of the) organisms and their environment ;
interacting together (in a given area) ;

10(c) Sun ;
10(d) any two from:
faster / quicker ;
requires less energy ;
idea that favourable traits are kept ;
reproduction still possible if plant is isolated ;

Question 11:

Topic – C4.1 Electrolysis

(a) Molten lead(II) bromide conducts electricity.
(i) When molten lead(II) bromide is electrolysed, lead is made at the cathode.
State the product at the anode.

…………………………………………………………………………………………………………………….

(ii) Explain why molten lead(II) bromide conducts electricity.

……………………………………………………………………………………………………………………
…………………………………………………………………………………………………………………….
(b) Aqueous copper(II) sulfate can be electrolysed using carbon electrodes.
Copper is formed at the cathode.
Construct the ionic half-equation for the formation of copper.
…………………………………………………………………………………………………………………….
(c) A student electrolyses aqueous copper(II) sulfate using copper electrodes.
The student weighs the electrodes before the experiment to find their mass.
After the electrolysis, the student washes and dries the electrodes and then weighs the electrodes again to find their mass.
Table 11.1 shows the results.

(i) The student forgot to record the mass of the cathode after the electrolysis.
Suggest the change in mass of the cathode in grams.
Write your answer in Table 11.1.
(ii) The anode loses mass.
Explain why the anode loses mass.

▶️Answer/Explanation

Ans: 11(a)(i) bromine / Br$_{2}$ ;
11(a)(ii) (lead (II) bromide) contains ions ;
(idea that the ions) can move ;

11(b) Cu$^{2+}$ + 2$^{e-}$ → Cu
formulae ;
balancing ;

11(c)(i) + 0.62 ;
11(c)(ii) any two from:

copper dissolves at the anode / anode dissolves ;
copper atoms become copper ions ;
copper ions move into solution ;

Question 12:

Topic – P3.2.4 Dispersion of light

Fig. 12.1 shows a ray of light refracted as it enters a glass block.

(a) Use Fig. 12.1 to calculate the refractive index of the glass block.
Give your answer to 3 significant figures.

refractive index = …………………………………………………
(b) Fig. 12.2 shows how the refractive index of glass varies with the wavelength of light used.

(i) Use Fig. 12.2 to determine the wavelength of light used in Fig. 12.1.

wavelength = …………………………………………….. m

(ii) Violet light has a wavelength of 4.0 × 10$^{-7}$m.
Red light has a wavelength of 7.0 × 10$^{-7}$m.
Describe how Fig. 12.2 shows that red light travels faster through glass than violet light.
………………………………………………………………………………………………………………………….
………………………………………………………………………………………………………………………….
(c) Fig. 12.3 shows the dimensions of the glass block.

The density of glass is 2.80g/cm$^{3}$.
Use Fig. 12.3 to calculate the mass of the glass block.

mass = ……………………………………………… g

▶️Answer/Explanation

Ans: 12(a) (n =) sin i / sin r or sin 53°/sin 31° ;
(n =) 1.55 ;

12(b)(i) (wavelength =) 4.8×10$^{-7}$(m) ;
12(b)(ii) refractive index is inversely proportional to speed ;
12(c) (volume =) 144 (cm$^{3}$ ) ;
(mass =) 2.8(0) × 144 ;
(mass = ) 403 (g) ;

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