3: Quantitative Chemistry · 2018-03-29 · In this reaction, one of the reagents is in excess. Calculate the moles of product formed. As there is a 2:1:2 ratio, then 0.6 moles of

Chemistry Paper 1 Flash Cards

3: Quantitative Chemistry

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Card Number: 1 Level of Question: Mastering Topic: 3 Quantitative chemistry Specification: 4.3.2

Chemistry Paper 1

5 moles of Magnesium reacts with 7 moles of Sulfuric acid in the following reaction:

Mg + H2SO4 MgSO4 + H.

In this reaction, one of the reagents is in excess. Calculate the moles of product formed.

As there is a 1:1:1:1 ratio, then the maximum of 5 moles of Hydrogen can be produced when 5 moles of Magnesium is used.

Magnesium is said to be the limiting reactant and sulfuric acid is in excess and so not all of it reacts.



Chemistry Paper 1

0.6 moles of magnesium reacts with 0.4 moles of oxygen to form magnesium oxide in the following reaction:

2Mg + O2 2MgO.


As there is a 2:1:2 ratio, then 0.6 moles of Magnesium reacts with 0.3 moles of oxygen to form 0.6 moles of magnesium oxide.

Magnesium is said to be the limiting reactant and oxygen is in excess.



Chemistry Paper 1

0.6 moles of magnesium reacts with 0.6 moles of oxygen to form magnesium oxide in the following reaction:

2Mg + O2 2MgO


As there is a 2:1:2 ratio, then 0.6 moles of Magnesium reacts with 0.3 moles of oxygen to form 0.6 moles of magnesium oxide.

Magnesium is said to be the limiting reactant and oxygen is in excess.



Chemistry Paper 1

What is meant by the term 'limiting reactant'?

The reactant in a reaction that determines the amount of products formed. This will leave any reactant in excess not all reacting.



Chemistry Paper 1

Use the following information to deduce and balance a symbol equation for the following reaction: 3.6g of Magnesium reacts with 2.4g of oxygen to make 6.0g of magnesium oxide

(MgO).

Mg moles = 3.6/24 = 0.15 moles;

O2 moles = 2.4/16 = 0.075 moles;

MgO moles = 6/40 = 0.15 moles.

Convert these to the simplest whole number ration by dividing all of these answer by the smallest 0.075).

This shows then that 2 moles of Mg reacts with 1 mole of O2 to form 2 moles of MgO. Therefore, the balanced symbol equation is 2Mg + O2 2MgO



Chemistry Paper 1

Use the following information to deduce and balance a symbol equation for the following reaction: 1.62g of Aluminium reacts with 6.4g of chlorine (Cl2) to make 8.02g of aluminium

chloride (AlCl3)

Al moles = 1.62/27 = 0.06 moles;

Cl2 moles = 6.4/71 = 0.09 moles;

AlCl3 moles = 8.02/133.5 = 0.06 moles.

Convert these to the simplest whole number ration by dividing all of these answer by the smallest 0.06).

This shows then that 2 moles of Al reacts with 3 moles of Cl2 to form 2 moles of AlCl3 Therefore, the balanced symbol equation is 2Al + 3Cl2 2AlCl3



Chemistry Paper 1

Use the following information to deduce and balance a symbol equation for the following reaction: 1.1g of propane (C3H8) reacts with 4.0g of oxygen (O2) to produce 3.3g of carbon

dioxide and 1.8g of water.

C3H8 moles = 1.1/44 = 0.025 moles;

O2 moles = 4.0/32 = 0.125 moles;

CO2 moles = 3.3/44 = 0.075 moles;

H2O moles = 1.8/18 = 0.1 moles.

Convert these to the simplest whole number ration by dividing all of these answer by the smallest (0.025). This shows then that 1 mole of C3H8 reacts with 5 moles of O2 to form 3

moles of CO2 and 4 moles of H2O.

Therefore, the balanced symbol equation is C3H8 + 5O2 3CO2 + 4H2O



Chemistry Paper 1

Using moles, calculate how much sodium hydroxide is needed to make 5.00g of sodium sulphate.

2NaOH + H2SO4 Na2SO4 + 2H2O

(Ar: Na = 23, O = 16, H = 1, S = 32)

Mass of Na2SO4 = 5.00g and its Mr 142, therefore mass ÷ Mr = 0.035 moles.

As 2 moles of NaOH produces 1 mole of Na2SO4, the number of moles of NaOH is

2 x 0.035 = 0.07moles.

Therefore the mass of NaOH needed is 0.07 x Mr of NaOH = 0.07 x 40 = 2.8g



Chemistry Paper 1

Using moles, what mass of sodium chloride is produced when 5.3 g of sodium carbonate reacts with excess dilute hydrochloric acid?

(Ar: Na = 23, C = 12, O = 16, Cl = 35.5)

For this reaction, you need to use a balanced equation:

Na2CO3 + 2HCl → 2NaCl + H2O + CO2

This shows that 1 mole of sodium carbonate produces 2 moles of sodium chloride. So The Mr of sodium carbonate is 106 and the Mr of sodium chloride is 58.5.

So mass ÷ Mr of sodium carbonate = 5.3 ÷ 106 = 0.05 moles.

Therefore, this produces 0.05 x 2 = 0.1 moles of sodium chloride. The mass is therefore calculated by 0.1 x 58.5 = 5.85g


Card Number: 10 Level of Question: Mastering Topic: 3 Quantitative chemistry Specification:

Chemistry Paper 1

When 12 g of carbon is burned in air, 44 g of carbon dioxide is produced.

Using moles, what mass of carbon is needed to produce 11 g of carbon dioxide?

Moles of Carbon Dioxide = Mass ÷ Mr = 11/44 = 0.25 moles.

As it is a 1:1 ratio, 0.25 moles of carbon is required.

Therefore, mass = moles x Mr = 0.25 x 12 = 3g



Chemistry Paper 1

Using ratios, calculate how much sodium hydroxide is needed to make 5.00g of sodium sulphate. 2NaOH + H2SO4 Na2SO4 + 2H2O.

(Ar: Na = 23, O = 16, H = 1, S = 32)

Mr of NaOH = 40.

Mr of Na2SO4 = 142.

As 2 moles of NaOH produces 1 mole of Na2SO4,

80g of NaOH produces 142g of Na2SO4.

From ratios we know that 80 ÷ 142 = 0.563g of NaOH produces 1g of Na2SO4,

so 2.82g of NaOH will produce 5.00g of Na2SO4.



Chemistry Paper 1

Using ratios, what mass of sodium chloride is produced when 5.3 g of sodium carbonate reacts with excess dilute hydrochloric acid?

(Ar: Na = 23, C = 12, O = 16, Cl = 35.5)

For this reaction, you need to use a balanced equation:

Na2CO3 + 2HCl → 2NaCl + H2O + CO2

This shows that 1 mole of sodium carbonate produces 2 moles of sodium chloride.

So The Mr of sodium carbonate is 106 and the Mr of sodium chloride is 58.5.

Therefore, 106g of sodium carbonate will produce 117g of sodium chloride. The ratio of sodium chloride to sodium carbonate is 117 ÷ 106 x mass used (5.3g) = 5.85g


Card Number: 13 Level of Question: Secure Topic: 3 Quantitative chemistry Specification: 4.2.2.1

Chemistry Paper 1

What do the following state symbols mean: (s), (l), (g) and (aq)

(s) Solid,

(l) liquid,

(g) gas,

(aq) aqueous



Chemistry Paper 1

What is the relative formula mass of water?

(Ar H = 1, O = 16)

H = 2 x 1 = 2; O = 16 x 1 = 16.

So 2 + 16 = 18


Card Number: 15 Level of Question: Secure Topic: 3 Quantitative chemistry Specification: 4.3.1.2 )

Chemistry Paper 1

What is the relative formula mass of sodium chloride (NaCl)?

(Ar Na = 23, Cl = 35.5)

23 + 35.5 = 58.5



Chemistry Paper 1

What is the relative formula mass of sulfuric acid (H2SO4)?

(Ar H = 1, S = 32, O = 16)

2 + 32 + 64 = 98



Chemistry Paper 1

What is the relative formula mass of Magnesium Nitrate (Mg(NO3)2)?

(Ar Mg = 24, N = 14, O = 16)

24 + (2 x 62) = 148



Chemistry Paper 1

What is the relative formula mass of sodium chloride (NaCl)?

(Ar Na = 23, Cl = 35.5)

From the periodic table, this is the mass of the element and is made up of the total number of protons and neutrons. It is the mass compared to Carbon-12and takes into account each

isotope.



Chemistry Paper 1

How is the relative formula mass calculated?

This is the combined mass of all the elements in the compound,

e.g. MgCl2 Is calculated by Mg – Ar is 24, Cl – Ar is 35.5 where Ar = Relative Atomic Mass.

So the formula mass is 24 + 35.5 + 35.5 = 95



Chemistry Paper 1

What is meant by the term relative formula mass?

The total of the relative atomic masses, added up in the ratio shown in the chemical formula, for a substance.


Card Number: 21 Level of Question: Secure Topic: 3 Quantitative chemistry Specification: 4.3.2

Chemistry Paper 1

What is the percentage by mass of oxygen (O) in sodium hydroxide (NaOH)?

(Ar: Na = 23, O = 16, H = 1)

The Mr of NaOH = 23 + 16 + 1 = 40,

so 16/40 x 100 = 40%



Chemistry Paper 1

What mass of carbon dioxide is formed when 12g of carbon is burned in air?

(Ar: C = 12, O = 16)

From the Ar we know that 12g or carbon will produce 44g of carbon dioxide.



Chemistry Paper 1

When 5.0 g of calcium carbonate is decomposed by heating, it produces 2.2 g of carbon dioxide.

Using ratios, what mass of calcium carbonate is needed to produce 8.8 g of carbon dioxide?

If 5.0g of CaCO3 decomposed to produce 2.2g of carbon dioxide, then for 8.8g of carbon dioxide to be produced, you will need 4 times as much calcium carbonate, so 20g.



Chemistry Paper 1

When 12 g of carbon is burned in air, 44 g of carbon dioxide is produced.

Using ratios, what mass of carbon is needed to produce 11 g of carbon dioxide?

12g of Carbon will make 44g of carbon dioxide.

As 11g of carbon dioxide is 4 times smaller, we will need 4 times less carbon, so 3g.



Chemistry Paper 1

Balance the following equation: H2O H2 + O2

2H2O 2H2 + O2



Chemistry Paper 1

Balance the following equation: Mg + HCl MgCl2 + H2

Mg + 2HCl MgCl2 + H2



Chemistry Paper 1

Balance the following equation: H2 + N2 NH3

3H2 + N2 2NH3



Chemistry Paper 1

What is meant by the term 'conservation of mass'?

In a chemical reaction the total mass of the reactants must equal the total mass of the products.



Chemistry Paper 1

Quote 0.0012462 to 4 significant figures

0.001246



Chemistry Paper 1


0.00125



Chemistry Paper 1


0.0012



Chemistry Paper 1

Quote 123.145to 4 significant figures.

123.1


Card Number: 33 Level of Question: Secure Topic: 3 Quantitative chemistry Specification: 4.3.2 )

Chemistry Paper 1


123



Chemistry Paper 1


120



Chemistry Paper 1

Quote 645898 to 4 significant figures.

645900



Chemistry Paper 1


646000



Chemistry Paper 1


650000


Card Number: 38 Level of Question: Secure Topic: 3 Quantitative chemistry Specification: 4.3.2 )

Chemistry Paper 1

Quote 3.765898 to 4 significant figures.

3.766



Chemistry Paper 1


3.77



Chemistry Paper 1


3.8



Chemistry Paper 1

How many grams are in 5kg?

5000g



Chemistry Paper 1

How many moles are there in 4g of methane (CH4)?

(Ar: C = 12, H = 1)

Number of moles = 4 ÷ 16 = 0.25 mol



Chemistry Paper 1

How many moles are there in 2g of water?

(Ar: H = 1, O = 16)

Mr of H2O = (1 x 2) + 16 = 18

Number of moles = 2 ÷ 18 = 0.1 mol



Chemistry Paper 1

What is the formula that links mass, number of moles and relative formula mass?

Number of moles = mass ÷ Relative formula mass



Chemistry Paper 1

What is avogadro's constant?

6.02 x 1023 - This is the number of atoms in 12g of C-12.



Chemistry Paper 1

What is meant by the term mole?

The amount of substance in the relative atomic/formula mass of a substance in grams



Chemistry Paper 1

How many cm3 are there in 1 dm3?

1000



Chemistry Paper 1

What is the concentration of sodium chloride solution if 50g of sodium chloride is dissolved in 2dm3 of solution?

25 g/dm3



Chemistry Paper 1

What is 0.5dm3 in cm3?

0.5 x 1000 = 500cm3



Chemistry Paper 1

What is meant by 'thermal decomposition'?

This is where high temperatures cause a substance to break down into simpler substances.


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3: Quantitative Chemistry · 2018-03-29 · In this reaction, one of the reagents is in excess. Calculate the moles of product formed. As there is a 2:1:2 ratio, then 0.6 moles of