Topic 6 Quantitative analysis, equilibrium, fuel cells Flashcards
- What is the relative formula mass of magnesium oxide, MgO?
40
- What is the relative formula mass of water, H2O?
18
- What is the relative formula mass of carbon dioxide, CO2?
44
- What is the relative formula mass of sulfuric acid, H2SO4?
98
- What is the empirical formula of a compound with molecular formula C2H6?
CH3
- What is the empirical formula of a compound with molecular formula C6H6?
CH
- H What is the mass of 1 mole of sodium chloride, NaCl?
58.5 g
- H What is the mass of 0.1 mole of sulfur dioxide, SO2?
6.4 g
- What mass of water should be formed when 2 g of hydrogen reacts with 16 g of oxygen?
18 g
- What mass of magnesium oxide should be formed when 2.4 g of magnesium reacts with 1.6 g of oxygen?
4.0 g
- What is meant by the actual yield?
the actual amount of product formed in a reaction
- What is meant by the theoretical yield?
the maximum mass of product calculated from the balanced equation
- What is the formula for calculating percentage yield?
(actual yield/theoretical yield) × 100%
- What is the percentage yield if the actual yield is 60 g and the theoretical yield is 100 g?
60%
- What is the percentage yield if the actual yield is 5.5 g and the theoretical yield is 10 g?
55%
- What is the percentage yield if the actual yield is 15 g and the theoretical yield is 20 g?
75%
- What is the percentage yield if the actual yield is 0.1 g and the theoretical yield is 0.5 g?
20%
- Give one reason why the actual yield is less than the theoretical yield.
incomplete reaction, practical losses or competing reactions
- What is the relative formula mass of calcium hydroxide, Ca(OH)2?
74
- What is the relative formula mass of magnesium nitrate, Mg(NO3)2?
148
- What is meant by a solute?
a substance that dissolves in a liquid
- What is meant by a solvent?
the liquid that dissolves the solute
- How many cm3 are there in 1 dm3?
1000
- What is the concentration, in g dm-3, of 100 cm3 of a solution containing 2 g of solute?
20 g dm-3
- What is the concentration, in g dm-3, of 500 cm3 of a solution containing 5 g of solute?
5 g dm-3
- What is the concentration, in g dm?3, of 250 cm3 of a solution containing 4 g of solute?
4 g dm-3
- What is the amount, in moles, of hydrochloric acid, HCl, in 36.5 g?
1 mol
- What is the amount, in moles, of sodium hydroxide, NaOH, in 20 g?
0.5 mol
- What is the concentration of hydrochloric acid, in mol dm-3, if the concentration is 36.5 g dm-3?
1 (mol dm-3)
- What is the concentration of sodium hydroxide in mol dm-3, if the concentration is 20 g dm-3?
(0.5 (mol dm-3))
- What are the two substances formed when an acid reacts with an alkali?
salt and water
- What type of reaction takes place when an acid reacts with an alkali?
neutralisation
- Is potassium hydroxide an acid, an alkali or a salt?
alkali
- Is sodium sulfate an acid, an alkali or a salt?
salt
- What is used to show that a solution is acidic, alkaline or neutral?
an indicator
- What colour is phenolphthalein in an acidic solution?
colourless
- What colour is methyl orange in an alkaline solution?
yellow
- What measuring instruments are used to measure the accurate volumes of acid and alkali in a titration?
burette and pipette
- H How many moles of solute are there in 2 dm3 of 0.1 mol dm-3 hydrochloric acid?
0.2 mol
- H How many moles of solute are there in 100 cm3 of 0.1 mol dm-3 hydrochloric acid?
0.01 mol
- What is the abbreviation used for the mole, the unit for amount of substance?
mol
- How many particles are there in 1 mole of particles?
6.02 × 1023
- The mass of 1 mole of carbon atoms is 12 g. What is the mass of 2 moles of carbon atoms?
24 g
- 2 g of hydrogen gas contains 1 mole of hydrogen molecules. How many moles are there in 1 g of hydrogen molecules?
0.5 mol
- Each water molecule contains three atoms. How many moles of atoms are there in 2 moles of water molecules?
6 mol
- The relative formula mass of chlorine gas is 71. What is the mass of 1 mole of chlorine gas?
71 g
- What happens to the volume of a gas if its pressure is increased but its temperature is kept the same?
volume decreases
- What happens to the volume of a gas if its temperature is increased but its pressure is kept the same?
volume increases
- What is 100 dm3 in cm3?
100 000 cm3
- 0.5 mol of salt is dissolved in 2 dm3 of water. What is the concentration of the solution?
0.25 mol dm–3
- What are the chemical symbols for the elements nitrogen, potassium and phosphorus?
N, P, K
- What two gases react together to produce ammonia in the Haber process?
nitrogen, hydrogen
- What temperature is used in the Haber process?
450 °C
- What pressure is used in the Haber process?
200 atmospheres
- Why is iron used in the Haber process?
It is the catalyst/it makes the reaction go faster.
- Is ammonium sulfate soluble or insoluble in water?
soluble
- Name the acid needed to produce ammonium nitrate.
nitric acid
- Name the acid needed to produce ammonium sulfate.
sulfuric acid
- What method produces a solution containing only salt and water from an acid and alkali?
titration/neutralisation
- There is only one product in the Haber process. What is the atom economy of the process?
100%
- Write down or describe the symbol used for reversible reactions.
double headed arrow
- Do the reactions keep going when a reversible reaction reaches equilibrium?
yes
- Do the concentrations of the reacting substances change at equilibrium?
no
- What compound is manufactured in the Haber process?
ammonia
- If the temperature is increased in a dynamic equilibrium, does the position move towards the endothermic reaction or towards the exothermic reaction?
towards the endothermic reaction
- If the pressure is increased in a dynamic equilibrium involving gases, does the position move towards the fewest number of moles of gas?
yes
- Compared with the theoretical yield, is the actual yield of product usually less, the same or more?
less
- What happens to the rate of a reaction if the temperature is increased?
it increases
- What happens to the rate of a reaction if a suitable catalyst is added?
it increases
- Does a catalyst get used up in the reaction it catalyses?
no
- Which is more reactive, zinc or iron?
zinc
- Name the ion released by acids when they dissolve in water.
hydrogen/H+
- Name the product formed when hydrogen reacts with oxygen.
water
- What charged particles move through the liquid during electrolysis?
ions
- In what type of reaction is energy transferred to the surroundings?
exothermic
- What is the unit for electrical potential difference?
volt/V
- In electrolysis, what do we call the ionic compounds that are decomposed?
electrolytes
- What is the approximate voltage of a typical AA battery?
1.5 V
- What fuel is used in a hydrogen–oxygen fuel cell?
hydrogen
- What is oxidation?
reaction with oxygen/gain of oxygen/loss of electrons