Scribd
Upload
168 views2 pages

1 TUTORIAL - Mole Concept

This tutorial document discusses concepts related to the mole including: 1) Calculating the volume of NH3 produced in a reaction of N2 and H2 gases. 2) Determining the relative molecular mass of a monobasic acid given reaction quantities. 3) Identifying the simplest formula for a compound containing 50% S and 50% O by mass. 4) Calculating the value of x in a formula for a hydrated ionic salt given masses before and after heating. 5) Calculating the mass of water produced from a reaction of oxygen and excess hydrogen gases.

Uploaded by

Giovanni Slack
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as DOCX, PDF, TXT or read online on Scribd
168 views2 pages

1 TUTORIAL - Mole Concept

This tutorial document discusses concepts related to the mole including: 1) Calculating the volume of NH3 produced in a reaction of N2 and H2 gases. 2) Determining the relative molecular mass of a monobasic acid given reaction quantities. 3) Identifying the simplest formula for a compound containing 50% S and 50% O by mass. 4) Calculating the value of x in a formula for a hydrated ionic salt given masses before and after heating. 5) Calculating the mass of water produced from a reaction of oxygen and excess hydrogen gases.

Uploaded by

Giovanni Slack
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as DOCX, PDF, TXT or read online on Scribd
You are on page 1/ 2

TUTORIAL: Mole concept

1. Item 1 refers to the following equation which shows the production of ammonia.
N2(g) + 3H2(g) ↔ 2 NH3(g)
If 10 cm3 of nitrogen reacts with 30 cm3 of hydrogen at STP, what volume of NH3 is
produced?
A. 10 cm3 B. 15 cm3 C. 20 cm3 D. 40 cm3
2. For complete reaction, 0.25 g of a monobasic acid requires 10 cm3 of 0.2 mol dm-3 sodium
hydroxide. What is the relative molecular mass of the acid?
A. 12.5 B. 62.5 C. 125 D. 250
3. The simplest formula for a compound that contains 50 % S and 50 % 0 by mass is
A. SO B. SO2 C. S2O D. S2O4

4. When 86 g of the ionic salt, CaSO4.xH2O is heated so that all of its water of
crystallization is driven off and 68.0 g of CaSO4. remain, the value of x is

A. 1 B. 2 C. 3 D. 4

5. If 16.4 g of oxygen gas react with excess hydrogen, what mass of water is produced?

2H2(g) + O2(g) → 2H2O(g)


A. 9.23 g
B. 18.5 g
C. 20.4 g
D. 23.9 g
E. 36.9 g

6. When H2SO4 is neutralized by KOH in aqueous solution, the net ionic equation is:
A. SO42- + 2K+ → K2SO4 (aq)
B. SO42- + 2K+ → K2SO4 (s)
C. H+ + OH- → H2O (l)
D. H2SO4 + 2OH- → 2H2O (l) + SO4

7. This question looks at the reaction of sodium with water and with oxygen.

A chemist reacted 0.0500 mol of sodium with water to form 50.0 cm3 of aqueous
sodium hydroxide.

2Na(s) + 2H2O(l) → 2NaOH(aq) + H2(g)

(i) What mass of Na was reacted?

mass = ............................... g
[1]
(ii) Calculate the volume of H2, in dm3, that would be produced at standard
temperature and pressure, s.t.p.

1 mol of gas molecules occupies 22.4 dm3 at s.t.p.

volume = .......................... dm3


[2]

(iii) Calculate the concentration, in mol dm–3, of NaOH that was formed.

concentration = ................... mol dm–3


[1]
[Total 4 marks]

8. A 0.2500 g sample of a compound known to contain carbon, hydrogen and oxygen


undergoes complete combustion to produce 0.3664 g of CO2 and 0.1500 g of H2O. What is
the empirical formula of this compound?

You might also like