31. A student investigated the reaction between dilute hydrochloric acid and sodium carbonate. One experiment involved measuring the volume of carbon dioxide produced when solid sodium carbonate was used.Time/s103040506070VolumeCO2/cm325324149a) Calculate the average rate in cm3/s of carbon dioxide produced between 10 and 40 seconds.b) Calculate the average rate in cm3/s of carbon dioxide produced in the first 40seconds.c) When did the reaction finish?
7The table shows the numbers of protons, electrons and neutrons in four particles, W, X, Y and Z. Which pair of particles are isotopes?A. W and XB. W and YC. X and YD. Y and Z
8Bromine has two isotopes Bromine has two isotopes. One has a mass number of 81 and the other has a mass number of 79. The relative atomic mass of bromine is 80. What does this tell you about the percentage of each isotope in bromine?Chlorine has two isotopes. One has a mass number of 35 and the other has a mass number of The relative atomic mass of chlorine is 35.5.Which isotope of chlorine is most abundant in the sample?
9Find the number of protons, neutrons and electrons in each of the following; 1. 2. 3. 4.
10Solid ionic compounds do not conduct electricity because; The ions are not free to moveThe electrons are not free to moveSolid substances never conduct electricityThere are no charged particles in ionic compoundsWhich substance exists as diatomic moleculesSodium chlorideNitrogen monoxideSilicon tetrachlorideSulfur dioxide
11Draw a diagram to show how the outer electrons are shared in a molecule of; Hydrogen chlorideHydrogen sulfideNitrogen fluorideWaterMethane
12Which of the following diagrams could be used to represent the structure of a covalent network?
13The table gives information about some substances. Melting point/0CBoiling point/ 0CConduction asA solidA liquidA18903380YesB9631560NoC14552730D-183-164E17002230F7121418Identify the two ionic compounds.Identify the covalent networkIdentify the covalent molecular compoundIdentify the substance which is a gas at room temperature (210C)
14A substance X, has a melting point of 996⁰C and a boiling point of 1704⁰C. It only conducts electricity when molten or when dissolved in water.The structure of X is likely to beIonicMetallicCovalent networkCovalent molecular
21Precipitation is when two solutions react to form an insoluble product Precipitation is when two solutions react to form an insoluble product. Which of the following pairs of solutions would react together to produce a precipitate?Silver (I) nitrate + sodium chlorideCopper (II) sulphate + sodium nitrateMagnesium chloride + lithium nitrateBarium chloride + potassium nitrateWhen barium nitrate solution is mixed with sodium sulphate solution, the name of the precipitate formed isbarium chloridebarium sulphatesodium chloridesodium nitrate
22Which of the following oxides would dissolve in water to produce an acidic solution? (You may wish to consult your data booklet)sulphur dioxideiron (III) oxidecopper (II) oxidesodium oxideWhich of the following gases would dissolve in water to produce an alkaline solution?Carbon dioxideNitrogen dioxideAmmoniaMethane
23Which of the following reactions would not result in the formation of a salt? Acid + alkaliAcid + reactive metalAcid + alcoholAcid + carbonateWhich of the following is not a salt?Sodium chlorideLithium sulphatePotassium hydroxideCopper (II) nitrate
24Name the product (s) of the following neutralisation reactions; Magnesium and hydrochloric acidPotassium hydroxide and sulfuric acidMagnesium carbonate and hydrochloric acidCalcium carbonate and nitric acidAmmonia and sulfuric acid
25Which of the following statements correctly describes the concentration of H+ (aq) and OH- (aq) ions in an acidic substance when compared to pure water?The concentration of H+ (aq) and OH- (aq)ions are zero.The concentration of H+ (aq) and OH- (aq)ions are equal.The concentration of H+ (aq) is higher than OH-(aq) ions.The concentration of H+ (aq) is lower than OH- (aq) ions.
26Which line in the table correctly describes what happens to a dilute solution of hydrochloric acid when water is added to it?