## Higher tier only calculations - Edexcel

### 1

What is the mass of 5 moles of carbon? (Ar of Carbon = 12)

### 2

How many moles water (H2O) are in 90 g of water? (Ar of Hydrogen = 1, Ar of O = 16)

### 3

How many moles are in 2 g of solid sodium hydroxide (NaOH)? (Ar of Na = 23, Ar of O = 16, Ar of H = 1).

### 4

How many molecules are there in 0.25 moles of methane, CH4? (Assume Avogadro's Constant is 6 x 1023).

### 5

How many atoms are there in 3.4 g of ammonia (NH3)? (Ar of N = 14, Ar of H = 1). Assume Avogadro's constant is 6 x 1023.

### 6

How many oxygen atoms are in 1.1 g of carbon dioxide, CO2? (Ar of C = 12 , Ar of O = 16). Assume Avogadro's constant is 6 x 1023.

### 7

How many ions are contained in 9.4g of potassium oxide, K2O? (Ar of K = 39, Ar of O = 16). Assume Avogadro's constant is 6 x 1023.

### 8

What is the reactant that is completely used up in a chemical reaction called?

### 9

What mass of hydrogen is produced when 36 g of magnesium reacts completely with excess sulfuric acid? (Ar of Mg = 24; Mr of H2 = 2)

The balanced equation is: Mg(s) + H2SO4(aq) → MgSO4(aq) + H2(g).

### 10

If 1.6 g of sulfur combines with 2.4 g of oxygen, how many moles of oxygen will combine with 1 mole of sulfur? (Ar of S is 32; Ar of O is 16)