Worksheets3.1.2.2 The mole + Avogadro constant
Total questions: 23
Worksheet time: 12mins
How many protons are there in 6.0 g of nitrogen gas?
Avogadro constant, L = 6.022 × 1023 mol–1
1.3 × 1023
9.0 × 1023
1.8 × 1024
3.6 × 1024
A solution of volume 500 cm3 contains 150 g of ammonia.
What is the concentration, in mol dm–3, of ammonia in this solution?
0.51
8.82
16.7
17.6
A gas cylinder contains 5.0 kg of propane.
How many propane molecules are in the cylinder?
The Avogadro constant, L = 6.022 × 1023 mol–1
6.8 × 1022
7.2 × 1022
6.8 × 1025
7.2 × 1025
Which sample of liquid has the greatest volume?
500 mg of pentane (density = 0.63 g cm–3)
650 mg of propan-1-ol (density = 0.80 g cm–3)
1.20 g of dichloromethane (density = 1.33 g cm–3)
1.30 g of trichloromethane (density = 1.48 g cm–3)
Which of these contains the greatest number of atoms?
127 mg of iodine
1.54 × 10−4 kg of phosphorus
81.0 mg of carbon dioxide
1.70 × 10−4 kg of ammonia
Which sample contains the most molecules?
The Avogadro constant, L = 6.022 x 1023 mol−1
2.10 × 1022 molecules of methane, CH4
1.00 g of oxygen, O2
65.0 mg of hydrogen, H2
0.0300 mol of ethane, C2H6
Analysis of a sample of a chemical with formula C22H30N6O4S, showed that it contained 0.0195 mol of carbon.
What mass of nitrogen was present in the sample?
0.041 g
0.057 g
0.074 g
0.420 g
A solution of lead(ll) chloride (Mr = 278.2) contains 1.08 g of PbCl2 in 100 cm3 of solution. In this solution, the lead(ll) chloride is fully dissociated into ions.
What is the concentration of chloride ions in this solution?
3.88 × 10−3 mol dm−3
7.76 × 10−3 mol dm−3
3.88 × 10−2 mol dm−3
7.76 × 10−2 mol dm−3
What is the number of atoms in 0.0100 mol of NH3?
(The Avogadro constant L = 6.022 × 1023 mol−1)
6.02 × 1025
1.20 × 1023
1.81 × 1022
2.41 × 1022
Which of the following contains the most chloride ions?
15 cm3 of 3.40 × 10−2 mol dm−3 aluminium chloride solution
30 cm3 of 5.50 × 10−2 mol dm−3 calcium chloride solution
40 cm3 of 2.30 × 10−2 mol dm−3 hydrochloric acid
45 cm3 of 2.20 × 10−2 mol dm−3 sodium chloride solution
Which of these contains the most molecules?
0.0311 kg of carbon dioxide, CO2
29.6 g of carbon monoxide, CO
2.22 × 104 mg of oxygen, O2
13.3 g of ozone, O3
Which of the following contains the most chloride ions?
10 cm3 of 3.30 × 10−2 mol dm−3 aluminium chloride solution
20 cm3 of 5.00 × 10−2 mol dm−3 calcium chloride solution
30 cm3 of 3.30 × 10−2 mol dm−3 hydrochloric acid
40 cm3 of 2.50 × 10−2 mol dm−3 sodium chloride solution
In an experiment to identify a Group 2 metal (X), 0.102 g of X reacts with an excess of aqueous hydrochloric acid according to the following equation.
X + 2HCl --> XCl2 + H2
The volume of hydrogen gas given off is 65 cm3 at 99 kPa pressure and 303 K. The gas constant is R = 8.31 J K–1 mol–1. Which is X?
Barium
Calcium
Magnesium
Strontium
There are 392 mol of pure gold in a bar measuring 10 cm by 10 cm by 40 cm.What is the density of gold in kg dm−3?
193
19.3
1.93
0.193
In a car airbag, sodium azide (NaN3) decomposes to form sodium metal and nitrogen gas.
2NaN3(s) → 2Na(s) + 3N2(g)
The sodium metal then reacts with potassium nitrate to produce more nitrogen gas.
10Na(s) + 2KNO3(s) → N2(g) + 5Na2O(s) + K2O(s)
If 2.00 mol of sodium azide react in this way, how many molecules of N2 will be formed? (The Avogadro constant L = 6.022 × 1023 mol–1)
2.41 × 1024
1.93 × 1024
1.81 × 1024
9.63 × 1023
The Mr of hydrated copper sulfate (CuSO4.5H2O) is 249.6.
Which of the following is the mass of hydrated copper sulfate required to make 50.0 cm3 of a 0.400 mol dm−3 solution?
3.19 g
3.55 g
3.71 g
4.99 g
The removal of silicon dioxide with limestone in a blast furnace can be represented by the following equation.
CaCO3(s) + SiO2(s) → CaSiO3(l) + CO2(g)
The minimum mass of calcium carbonate needed to remove 1.00 tonne (1000 kg) of silicon dioxide is
0.46 tonne
0.60 tonne
1.67 tonne
2.18 tonne
The removal of silicon dioxide with limestone in a blast furnace can be represented by the following equation.
CaCO3(s) + SiO2(s) → CaSiO3(l) + CO2(g)
The volume of carbon dioxide, measured at 298 K and 1.01 × 105 Pa, formed in this reaction during the removal of 1.00 tonne (1000 kg) of silicon dioxide is
24.5 dm3
408 dm3
24.5 m3
408 m3
When 0.10 g of propane was burned the quantity of heat evolved was 5.0 kJ. The enthalpy of combustion of propane in kJ mol−1 is
−800
−1500
−2200
−2900
Silver oxide, Ag2O, can be reduced by passing hydrogen gas over the heated oxide. The maximum mass of silver that could be obtained from 2.32 g of silver oxide is
2.02 g
2.06 g
2.12 g
2.16 g
In a reaction which gave a 27.0% yield, 5.00 g of methylbenzene were converted into the explosive 2,4,6-trinitromethylbenzene (TNT) (Mr = 227.0). The mass of TNT formed was
1.35 g
3.33 g
3.65 g
12.34 g
Use the information below to answer this question.
A saturated solution of magnesium hydroxide, Mg(OH)2, contains 0.1166 g of Mg(OH)2 in 10.00 dm3 of solution. In this solution the magnesium hydroxide is fully dissociated into ions.
Which one of the following is the concentration of Mg2+(aq) ions in the saturated solution?
2.82 × 10−2 mol dm−3
2.00 × 10−3 mol dm−3
2.82 × 10−3 mol dm−3
2.00 × 10−4 mol dm−3
Which one of the following contains the greatest number of moles of methanol? (The Avogadro number (L) is 6.02 × 1023, the relative molecular mass (Mr) of methanol is 32.)
6.6 × 1022 molecules
3.3 g of methanol
2.5 × 10−3 m3 of methanol vapour at 300 K and 100 kPa
70 cm3 of 1.5 M aqueous methanol
