1 A 2 B 3 C The atomic number of Na is 11. How many electrons are there in a sodium ion, Na +? How many hydrogen atoms are there in the empirical formula of propene, C 3 H 6? What is the mass in grams of 1 mole of 7 Li? 73 23 20 3 4 D 5 E 6 F What is the total number of sub-atomic particles found in the nucleus of an atom of 35 Cl? How many neutrons are there in one atom of 24 Mg? 12 3 51 What is the mass of 5 one mole of 9 Be? 7 G 8 H 9 J How many molecules of oxygen (O 2 ) would combine with 1 atom of carbon (C) to form 1 molecule of carbon monoxide (CO)? ethanol, C 2 H 5 OH? 74 10 C = 12, The most common isotope of molybdenum is 98 Mo. The second most common isotope has 2 fewer neutrons than 98 Mo. What is the mass number of this isotope? 40
C 3 B 2 A 1 20 What mass of lithium is there in ½ a mole of the ionic compound made from Li + and O 2- ions? (A r of Li = 7) How many Na atoms are there in the empirical formula of the compound containing 43.4% Na, 11.3% C and 45.3% O? O = 16, Na = 23) 23 73 What is the total number of sub-atomic particles (protons, neutrons and electrons) in 1 atom of 7 Li? 3 F 6 E 5 D 4 How many more neutrons than protons does an atom of 79 Br have? 35 What mass of carbon is there in 0.5 moles of ethane, C 2 H 6? 5 51 3 (A r of C = 12) What percentage mass of ammonium nitrate (NH 4 NO 3 ) is nitrogen? N = 14, J 9 H 8 G 7 formula mass of the sulfate ion, SO 4 2-? 40 10 (A r values: O = 16, S = 32) 81 Br is an isotope of bromine. If a bromine nucleus has a relative positive charge of 35 how many neutrons are there in 1 atom of 81 Br? 74 What is the mass of 0.005 moles of calcium carbonate, CaCO 3? O = 16, Ca = 40)
10 How many hydrogen atoms are combined with 1 carbon atom in a molecule of methane, CH 4? K 11 L 12 The molecular formula of the alkane nonane is C 9 H 20. How many hydrogen atoms are there in the empirical formula of nonane? percentage mass of oxygen in carbon monoxide? 18 8 1 M 13 N 14 O 15 P percentage of sulfur in sulfuric acid, H 2 SO 4? O = 16, S = 32) What is the atomic number of the atom that has a mass number of 51 and has 28 neutrons in its nucleus? How many sulfide ions (S 2- ) are combined with 1 magnesium ion (Mg 2+ ) in magnesium sulfide? 9 4 12 16 Q 17 R 18 S An isotope of chlorine has 17 protons and 20 neutrons. What is its mass number? The relative atomic mass of an element is found by comparing the mass of its atoms to an isotope of carbon. How many neutrons does an atom of this isotope of carbon have? 16 0.5 chlorine atoms are there in 1 mole of PCl 5? 96
M 12 1 1095 tonnes of ammonia is produced from a reaction between nitrogen and methane. If the maximum theoretical yield of ammonia for this reaction is 1500 tonnes, what is the percentage yield? L The formula of hydrated copper sulfate is CuSO 4.5H 2 O. How many moles of water would be found in 4 moles of hydrated copper sulfate crystals? 8 18 11 K 10 What is the mass of 0.1 moles of magnesium oxide, MgO? (A r values: O = 16, Mg = 24) P hydrogen molecules are there in 2g of hydrogen gas? 15 O 14 Ethanol can be made by reacting ethene with steam. C 2 H 4 +H 2 O C 2 H 5 OH If 14g of ethene are used what is the maximum theoretical yield of ethanol? C = 12, 12 4 9 (A r of H = 1) N carbon dioxide would be made if 1760g of iron oxide was reduced to iron using carbon monoxide? Fe 2 O 3 +3CO 2Fe+3CO 2 (A r values O = 16, Fe = 56) 13 S 18 R 17 Q 16 An oxide of nitrogen is found to contain 0.56g of N and 1.6g of O. How many atoms of oxygen are there in the empirical formula? (A r values: N = 14, 96 0.5 A particular hydrocarbon molecule is found to contain 0.36g of C and 0.06g of H. If each molecule contains 12 hydrogen atoms how many carbon atoms are there in its molecular formula? C = 12) 16 mass of 2.18 moles of ammonia, NH 3? N = 14)
19 T 20 U 21 V oxygen atoms are there in 51 moles of water? Ca(OH) 2? O = 16, Ca = 40) water? 6 2 33 22 W 23 X 24 Y the compound that is made from Mg 2+ and O 2- ions? (A r values: Mg = 24, The empirical formula of a particular hydrocarbon is CH 2. How many hydrogen atoms are there in its molecular formula if the compound has 4 carbon atoms in each molecule? How many more protons are there than electrons in an aluminium ion, Al 3+? 7 35 37 25 Z CH 4? (A r values: H =1, C = 12) 46
V 21 U 20 T 19 33 iron atoms are there in 9 moles of Fe 2 O 3? A chemical reaction has a maximum theoretical yield of 1.50g of product. What is the percentage yield if only 1.11g of the product is formed? 2 6 percentage mass of copper in CuCO 3? O = 16, Cu = 63.5) Y 24 X 23 W 22 How many nitrate ions (NO - 3 ) are combined with 1 aluminium ion (Al 3+ ) in aluminium nitrate? 37 35 oxygen are needed to balance the equation C 5 H 12 +_O 2 5CO 2 +6H 2 O? 7 What is the percentage mass of carbon in glucose, C 6 H 12 O 6? C = 12, Z 25 46 zinc oxide would be produced if 16 moles of zinc was burned completely in air according the equation 2Zn + O 2 2ZnO?