C1.5 - Use of amount of substance in relation to volumes of gases Knowledge Test

Candidate Name:
1) What is the law of the conservation of mass?
2) Why must we ensure that chemical equations are balanced?
3) What do the multipliers in normal script before a chemical formula represent? Eg 2MgO
4) How do we calculate the relative formula mass (Mr) of a compound?
5) Why must the total relative formula mass of all of the reactants equal that of all of the products made?
6) When a gas is produced in a chemical reaction, why would the mass of the products appear to be less than that of the reactants?
7) Explain why in the reaction below the mass of the products would be greater than that of the reactants 2Mg (s) O2 (g) -> 2MgO (s)
8) What does the term uncertainty mean?
9) How would you represent the distrubtion of results to make estimations of uncertainty?
10) A pippette has an uncertainty of /-0.01mL. It is used three times in a practical. What is the mean measure of uncertainty?
11) (HT only) Chemical amounts are measured in moles. What is the symbol of the unit for moles?
12) (HT only)How can we calculate the mass of one mole of a substance?
13) (HT only)If you have one mole each of two different substances, what will they share in common?
14) (HT only)What does Avogadro's constant represent?
15) (HT only)What is the value of Avogadro's constant?
16) (HT only)Would there be any difference in the number of atoms in one mole of carbon (C) compared with the number of one mole of molecules of carbon dioxide (CO2)?
17) (HT only)Calculate the mass of one mole of C2H6
18) What units are used for the measurement of concentration of a solution?
19) What is the concentration of a solution that has 37g of solute dissolved in 100cm3? Give your answer in dm3.
20) (HT only) What is the equation that relates the mass of a solute, the volume of a solution and the concentration of the solution?
21) Why industrially is high atom economy important?
22) (HT only)Balance the equation and calculate the mass of the reactants and products of the balanced symbol equation: H2O2 --> H20 02
23) (HT only)In the following equation: Mg 2HCI --> MgCI2 H2 What is the ratio of magnesium (Mg) atoms react in comparison to that of hydrochloric acid (HCl)?
24) (HT only)CaCO3 2HCl ---> CaCl2 CO2 H2O Use the above equation to determine the mass of carbon dioxide produced if you react 10g of calcium carbonate with an excess of hydrochloric acid?
25) (HT only)Calculate the mass of iron produced when 32g of iron (III) oxide is completely reduced by aluminium. The reaction is shown in the symbol equation: Fe2O3 2Al ? 2Fe Al2O3
26) (HT only)How can you use the massess of reactants and products to balance a symbol equation?
27) (HT only) Reactants Sb = 488g Cl2 = 426g Products SbCl3= 914g Complete a symbol equation for the reaction above using the masses to balance the equation.
28) (HT only)How do you rearrange the moles equation to find the relative formulat mass? Moles = mass / RFM
29) (HT only)What is meant when a reactant is said to be in excess?
30) What is meant when a reactant is described as a limiting reactant?
31) (HT only) 2H2 O2 --> 2H2O You react 10g of oxygen with 10g of hydrogen. Only 11.25g of product is made the rest of the reactants remain unused. Suggest why the full mass of reactants did not react. What is the leftover unreacted substance?
32) (Chem only) Suggest why it is not always possible obtain the calculated amount of product from a reaction?
33) (Chem only) What does the term yield refer to?
34) (Chem only) What is percentage yield?
35) (Chem only) What is the formula for calculating percentage yield?
36) (Chem only) What mass of carbon dioxide is formed when 12 g of carbon is burned in air?
37) (Chem only) What is atom economy a measure of?
38) (Chem only) What is the formula for calculating percentage atom economy?
39) (Chem only) Hydrazine (N2H4) is used in some rocket fuels. Two different methods can be used to manufacture hydrazine. The reactions are: NH2Cl NH3 ? N2H4 HCl 2NH3 H2O2 ? N2H4 2H2O Calculate the atom economy for each reaction
40) (Chem only) How can a chemist in a chemical plant that makes rocket fuel prevent waste products being formed?
41) (Chem only) What is mol/dm3 the unit of measurement for?
42) (Chem only) How can we calculate the number of moles of solute in a given volume of a solution?
43) (Chem only) What technique can we use if the volumes of two solutions that react completely are known and the concentration of one solution is known, to calculate the concentration of the other solution.
44) (Chem only) How can we calculate the mass of a solute within a solution if we know the concentration in mol/dm3?
45) (Chem only) What is the difference between a strong and weak acid?
46) (Chem only) Do all gases occupy the same volume?
47) (Chem only) What volume does one mole of any gas occupy at room temperature and pressure?
48) (Chem only) How could you calculate the volume a gas would occupy if you were given the mass of gas made?
49) (Chem only) If you have 88g of CO2. What volume would it occupy?
50) (Chem only) In the reaction CH4 2O2 ? CO2 2H2O (at rtp) what volume of water vapour is produced when 2.4 dm3 of methane burns?
51) (Chem only) Rearrange the volume of gas equation to calculate the number of moles
52) How do the Big Ideas link to this topic?

a) Forces:

b) Particles:

c) Energy:

d) Cells: