Chemistry Paper 1 Jan 2024

Chemistry Paper 1 Jan 2024 50cm3 of 6.0 mol dm-3 of HCl is mixed with 90cm3 of 3.0 mol dm-3 of HNO3. What is the H+(aq) concentration in the resulting solution? - answers-n(HCl): c x v = 50 x 6 = 300 n(HNO3): c x v = 90 x 3 = 270 n(H+): 300 + 270 = 500 v(H+): 50 + 90 = 140cm3 c(H+): n/v = 4.07... = 4.1 mol dm-3 How many electrons are removed from 2.02 x 10-2 g of Ne(g) atoms to form Ne+(g) ions? - answers-n(Ne) = m/Mr = 2.02 x 10^-2/20 = 1.01 x 10^-3 (1.01 x 10^-3) x (6.02 x 10^23) = 6.02 x 10^20 What is the formula for percentage uncertainty? - answers-% uncertainty = (uncertainty/measured value) x number of measurements x 100 What is meant by the term isotopes? - answers-Atoms of an element with different numbers of neutrons. Define the term relative atomic mass - answers-The average mass of an atom of an element relative to 1/12th the relative atomic mass of carbon 12 a sample of antimony, Ar=121.8, was analysed and was found to consist of 60% 121Sb and one other isotope. Determine the mass number of the other isotope in the sample of antimony - answers-Isotopic mass = (mass x abundance) + (mass x abundance)/total abundance 121.8 = (60 x 121) + 40x/100 12180 = 7260 + 40x /40 = x = 123...