12 questions · 12 marks · ≈ 12 min
The equation for a reaction is shown.
Mg3N2 (s) + H2O (l) → Mg(OH)2 (aq) + NH3 (aq)
Which row gives the smallest whole-number coefficients required to balance the equation?
| Mg3N2 | H2O | Mg(OH)2 | NH3 | |
|---|---|---|---|---|
| A | 1 | 6 | 3 | 2 |
| B | 1 | 3 | 3 | 1 |
| C | 2 | 6 | 2 | 2 |
| D | 2 | 6 | 3 | 2 |
Choose your answer
Which ionic equation represents the reaction between aqueous calcium chloride and aqueous silver nitrate?
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Ca2+ (aq) + 2AgNO3 (aq) → 2Ag+ (s) + Ca(NO3)2 (aq)
CaCl2 (aq) + 2Ag+ (aq) → 2AgCl (s) + Ca2+ (aq)
Ca2+ (aq) + 2NO3- (aq) → Ca(NO3)2 (aq)
Ag+ (aq) + Cl- (aq) → AgCl (s)
Which ionic equation represents the reaction between aqueous sodium ethanoate and aqueous hydrochloric acid?
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CH3CO2- (aq) + HCl (aq) → CH3CO2H (aq) + Cl- (aq)
CH3CO2- (aq) + H+ (aq) → CH3CO2H (aq)
Na+ (aq) + Cl- (aq) → NaCl (aq)
CH3CO2Na (aq) + H+ (aq) → CH3CO2H (aq) + Na+ (aq)
A compound contains 52.2% carbon, 13.0% hydrogen and 34.8% oxygen by mass.
What is the empirical formula of this compound?
Choose your answer
CH2O
C4H13O2
C2H6O
C6H2O
A sample of hydrated calcium sulfate, CaSO4∙ x*H2O, has a relative formula mass of 172.2.
What is the value of x?
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1
2
3
4
A hydrated carbonate of an unknown Group 1 metal, X, has the formula X2CO3∙ 10H2O and a relative formula mass of 286.
What is the identity of X?
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Li
Na
K
Rb
The skeletal formula of phenazine is shown.
What is the empirical formula of phenazine?
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C6H4N
C6H6N
C12H8N2
C12H12N2
An additive in leaded petrol is composed of lead, carbon and hydrogen only. The compound contains 6.19% hydrogen and 29.7% carbon by mass.
What is the value of x in the empirical formula PbC8Hx?
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5
6
16
20
Hydrated copper(II) sulfate, CuSO4∙ x*H2O, has a relative formula mass of 231.6.
What is the value of x?
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2
3
4
5
An organic compound has the following composition by mass: C, 53.33%; H, 11.11%; O, 35.56%.
What is the empirical formula of the compound?
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C2H4O
C2H5O
C4H8O2
C4H10O2
A compound has the following composition by mass: H, 5.00%; N, 35.00%; O, 60.00%.
What is the identity of the compound?
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HNO2
HNO3
NH2OH
NH4NO3
A sample of compound M contains 1.46 g of carbon, 0.482 g of hydrogen and 1.69 g of nitrogen.
What is the empirical formula of M?
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CH2N
CH4N
C2H4N
C4HN4