Key Calculations quiz Loading... 1. To determine the formula of a metal oxide by combustion, magnesium is heated in a crucible. Why is a lid used?To keep the magnesium warmTo stop the escape of magnesium oxide smokeTo stop carbon dioxide escapingTo stop the escape of magnesiumQuestion 1 of 17 Loading... 2. 7.485 g of a hydrated copper(II) sulphate CuSO₄.xH₂O was heated producing 4.785g of anhydrous copper(II) sulphate. What is the formula of the hydrated salt?CuSO₄.4H₂OCuSO₄.7H₂OCuSO₄.5H₂OCuSO₄.10H₂OQuestion 2 of 17 Loading... 3. In the thermal decomposition of calcium carbonate, we might expect 50g of calcium carbonate to produce 28g of calcium oxide. If instead only 24g of calcium oxide is produced, what is the percentage yield?0.857 % 56 %0.56 %85.7 %Question 3 of 17 Loading... 4. What volume does 3 moles of carbon dioxide gas occupy (at rtp)?72 cm³8 cm³8 dm³72 dm³Question 4 of 17 Loading... 5. In a chemical reaction, the overall molar enthalpy is +87 kJ/mol. Is this reaction exothermic or endothermic?Depends on the temperature of the surroundingsExothermicEndothermicDepends on the reagentsQuestion 5 of 17 Loading... 6. Complete the following expression: mass = Mᵣ / amount (in moles)Aᵣ / Mᵣamount (in moles) / Mᵣamount (in moles) x MᵣQuestion 6 of 17 Loading... 7. An oxide of nitrogen contains 26% nitrogen and 74% oxygen and has a relative molecular mass of 108. Find the empirical and molecular formulae for the oxide.Empirical formula is N₂O₅. Molecular formula is also N₂O₅Empirical formula is N₄O₁₀. Molecular formula is N₂O₅Empirical formula is N₂O₅. Molecular formula is N₄O₁₀Empirical formula is NO₂.₅ Molecular formula is N₂O₅Question 7 of 17 Loading... 8. Name this piece of lab equipmentmeasuring cylinderburettepipettefunnelQuestion 8 of 17 Loading... 9. What mass of calcium bromide will fully react with 71g of chlorine?480 g200g120 g240 gQuestion 9 of 17 Loading... 10. What is meant by the term molecular formula?A chemical formula that shows the actual numbers of the different types of atoms in a moleculeA method of calculating the ratios of masses in an equationA chemical formula that shows the simplest ratio of the numbers of atoms in a compoundA method of calculating the mass needed to make a certain yield in an equationQuestion 10 of 17 Loading... 11. Use Q=mcΔT and c=4.18J/°C/g. A strip of magnesium is added to a beaker with 200cm³ of copper (II) sulfate. The temperature starts at 21.7°C and rises to a maximum of 23.1°C. What is the total heat energy change?1170 J2.153 kJ1247 J1944 kJQuestion 11 of 17 Loading... 12. State the expression for calculating molar concentrationMolar concentration = Amount (in moles) x volume (in cm³)Molar concentration = volume (in dm³) / Amount (in moles)Molar concentration = Amount (in moles)/volume (in dm³)Molar concentration = Amount (in moles)/volume (in cm³)Question 12 of 17 Loading... 13. Calculate the relative formula mass(Mr) of hydrated copper (II) sulfate (CuSO₄.5H₂O)180.5177.5249.5127Question 13 of 17 Loading... 14. What are the units for amount in Chemistry?mol/dm³g per 100g of solventGramsMolesQuestion 14 of 17 Loading... 15. A sample of carbon contained 98.90% carbon-12 and 1.10% carbon-13. Calculate the relative atomic mass of carbon((12x98.90)+(13x1.10))/100 = 12.01(12+13)/2 = 12.5(12x13)/100 = 1.56((13x98.90)+(12x1.10))/100 = 12.99Question 15 of 17 Loading... 16. A graph shows the solubility of sodium chloride in water at 50°C is 34g/100g. At that temperature, what mass of sodium chloride will dissolve in 200g water?0.68g0.34g17g68gQuestion 16 of 17 Loading... 17. State the units of molar enthalpy change.kJ/molJ/⁰C/molmol/⁰CkJ/⁰CQuestion 17 of 17 Loading... Related Posts:The entire quiz question bank!The entire quiz question bank (Double only)!Equilibria (triple) quizCondensation Polymers quizElectrolysis quizAlcohols & Carboxylic Acids quiz Hydr0Gen2020-02-16T17:35:16+00:00Categories: Uncategorized|Tags: Quiz, Topic: Key Calculations| Share This Story, Choose Your Platform! FacebookXRedditLinkedInTumblrPinterestVkEmail
