WorksheetsQuantitative chemistry
Total questions: 15
Worksheet time: 2hrs 49mins
Number of moles in 12.4 t of NaNO3 ÷ number of moles in 12.4 t of NaCl =
7.0
0.69
49.1
Two students complete the synthesis of paracetamol from 4-aminophenol as shown by the equation on the picture.
Both students react 2 moles of 4-aminophenol with excess ethanoyl chloride.
Student 1 makes 1.5 moles of paracetamol. Student 2 makes 220 g of paracetamol.
Which student has the better percentage yield?
(Don't worry about the complicated names, use the molecular formulas.)
Student 1, 76 %
Student 1, 75 %
Student 2, 74 %
Student 2, 73 %
According to Avogadro’s Law, as long as the pressure and temperature are kept the same, equal volumes of gases contain equal numbers of moles of gas. Under standard temperature and pressure (273 K and 101,325 Pa) 1 mole of any gas has a volume of 22.4 dm3. Use Avogadro’s law to find out which gas syringe contain identical numbers of moles of gas as the syringe A (on the picture).
Syringe F
Syringe G
Syringe H
Syringe I
Syringe J
In the following equation, what is the molar ratio between hydrochloric acid and copper(II) oxide?
2 HCl + CuO → CuCl2 + H2O
1 : 2
2 : 1
1 : 1
What is the empirical formula of octane C8H18?
CH2
C4H9
C8H18
In an experiment, the actual yield is 8.4 g but the theoretical yield is 17.0 g. what is the percentage yield?
24.7 %
50.6 %
49.4 %
When the equation below is balanced, what is the coefficient for oxygen?
__C2H2(g) + __O2(g) → __ CO2(g) + __ H2O(g)
2
3
4
5
Ethyne, C2H2, reacts with oxygen according to the equation below. What volume of oxygen (in dm3) reacts with 0.40 dm3 of C2H2? (STP)
2 C2H2(g) + 5 O2(g) → 4 CO2(g) + 2 H2O(g)
0.40
0.80
1.0
2.0
How many oxygen atoms are present in 0.0500 mol carbon dioxide?
3.01×1022
6.02×1022
6.02×1023
1.20×1024
What mass (g) of potassium hydroxide (KOH) is needed to make up 500 cm3 of a solution of concentration 0.2 mol.dm-3?
2.8
11.2
5.6
0.56
In an experiment, excess chlorine was passed over 31 g of hot phosphorus until all of it had reacted. If 208.5 g of white phosphorus chloride was formed work out the formula of phosphorus chloride.
PCl3
PCl6
PCl7
PCl5
Sodium reacts with water as follows.
2 Na(s) + 2 H2O(l) → 2 NaOH(aq) + H2(g)
1.15 g of sodium is allowed to react completely with water. The resulting solution is diluted to 250 cm3. Calculate the concentration, in mol.dm–3, of the resulting sodium hydroxide solution.
0.1
0.2
0.3
0.4
What mass of CO2 will be produced when 50 g of CaCO3 decomposes?
CaCO3 → CO2 + CaO
22 g
44 g
11 g
33 g
What is the percentage by mass of carbon in calcium carbonate CaCO3?
12
40
48
A student needs to add 8.75 × 10-3 moles of NaOH to neutralise the acid in his sample. How many cm3 of a 0.35 mol.dm-3 solution should he add?
25
15
0.25
250
