FREE AND STUDY GAMES ABOUT AQA ALEVEL

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FREE AND STUDY GAMES ABOUT AQA ALEVEL

CHEMISTRY EXAM QUESTIONS

Actual Qs and Ans Expert-Verified Explanation

This Exam contains:

-Guarantee passing score -766 Questions and Answers -format set of multiple-choice -Expert-Verified Explanation Question 1: What explains halogenoalkanes increased reactivity relative to alkanes?

Answer:

The polar carbon-halogen bond

Question 2: How can chiral carbons be identified?

Answer:

Carbon atoms with four different groups surrounding them

Question 3: Are making bonds exo/endothermic? Explain your answer

Answer:

Exo- energy is given out when bonds are made Question 4: Write the balanced redox half equation for the oxidation of iron(ii) to iron(iii)

Answer:

Fe2+ --> Fe3+ + e¯

Question 5: Describe the bonding in diamond

Answer:

Each carbon is bonded to 4 other carbons in a tetrahedral shape

Question 6: How are addition polymers named?

Answer:

Poly(name of original alkene)

Question 7: Define first ionisation energy

Answer:

The energy required to remove one mole of electrons from one mole of atoms in the gaseous state

Question 8: Which energy level are the outer electronsin, in period 3 elements?

Answer:

3rd Question 9: Calculate the concentration of the following in both mol dm-3 and g dm-3 0.400 moles of HCl in 2.00 litres of solution

Answer:

0.2 mol dm-3 , 7.3 g dm-3 Question 10: Describe what you would observe and give an equation for the reaction between [Fe(H20)6]2+ and a few drops of sodium hydroxide.

Answer:

Green solution forms a green precipitate [Fe(H2O)6]2+ + 20H- ---> [Fe(H20)4(OH)2 + 2H2O Question 11: What reagents and conditions are necessary for ammonia substitution of halogenoalkanes?

Answer:

Reflux in aqueous, alcoholic excess ammonia

Question 12: How does a catalyst work?

Answer:

"substance that speeds up reaction without being used up, They provide an alternative mechanism with lower activation energy.

Question 13: If 4 dm3 of hydrogen sulphide is burned in 10 dm3 of oxygen, what is the final volume of the mixture (give the volume of each gas at the end)? 2 H2S(g) + 3 O2(g) ? 2 H2O(g) +

• SO2(g)

Answer:

• dm3 O2, 4 dm3 H2O, 4 dm3 SO2, total 12 dm3 gas

Question 14: Write a balanced equation for silicon reacting with oxygen, including state symbols

Answer:

Si(s) + O2(g) ? SiO2(s)

Question 15: Where is ozone found and why is it beneficial?

Answer:

Upper atmosphere, absorbs harmful UV radiation

Question 16: How many moles are there in 39.0 g of Al(OH)3

Answer:

0.5 Question 17: What 3 elements could be bonded to hydrogen to give hydrogen bonding

Answer:

Oxygen, nitrogen or fluorine

Question 18: What is the conjugate acid of HNO3?

Answer:

H2NO3+

Question 19: Explain in detail the technique recrystallization.

Answer:

Dissolve the solute in the minimum volume of hot solvent, cool the solution to allow the crystals to form, remove the crystals by vacuum filtration, dry the resulting crystals in an oven.

Question 20: In which block are the transition metals?

Answer:

d block

Question 21: How is oxidation symbolized in an equation?

Answer:

[O]

Question 22: What is the unit of rate of reaction?

Answer:

mol dm-3 s-1

Question 23: Describe the structure and bonding in silicon dioxide

Answer:

giant covalent structure

Question 24: What is activation energy

Answer:

The minimum amount of energy required to break the bonds in the reactants to allow the reaction to occur Question 25: How does increasing the surface area of a solid increase the rate of reaction?

Answer:

More particles are exposed and are available to collide, resulting in more frequent collisions

Question 26: What is crude oil?

Answer:

A mixture of mainly alkanes that can be separated by fractional distillation Question 27: Write an equation with state symbols for the reactions of chlorine with water

Answer:

Cl2(g) + H2O(l) <--> HCl(aq) + HOCl(aq)

Question 28: Describe an additional way of making a buffer solution

Answer:

"Adding a measured amount of hydroxide ions to a weak acid