Calculations quiz Loading... 1. 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 NO₂.₅ Molecular formula is N₂O₅Empirical formula is N₄O₁₀. Molecular formula is N₂O₅Empirical formula is N₂O₅. Molecular formula is N₄O₁₀Question 1 of 9 Loading... 2. A sample of bromine contained the two isotopes in the following proportions: bromine-79 = 50.7% and bromine-81 = 49.3%. Calculate the relative atomic mass of bromine((81x50.7)+(79x49.3))/100 = 80.01(81 + 79)/2 = 80((79x50.7)+(81x49.3))/100 = 79.99(81x79)/100 = 63.99Question 2 of 9 Loading... 3. Explain why atoms are neutralThe numbers of protons and neutrons are equalThe number of electrons is evenThe numbers of electrons and neutrons are equalThe numbers of electrons and protons are equalQuestion 3 of 9 Loading... 4. What is the relative atomic mass (Aᵣ) of a helium atom?8246Question 4 of 9 Loading... 5. To determine the formula of a metal oxide by combustion, magnesium is heated in a crucible. Why is a lid lifted from time to time?To allow some magnesium oxide smoke to escapeTo stop the crucible heating up too muchTo allow carbon dioxide to escapeTo allow oxygen in so the magnesium fully reactsQuestion 5 of 9 Loading... 6. Calculate the relative formula mass(Mr) of calcium hydroxide (Ca(OH)₂)58747338Question 6 of 9 Loading... 7. How many electrons in the outer shell of group 4 elements?3504Question 7 of 9 Loading... 8. What is the empirical formula of a compound in which 0.48 g of carbon combines with 0.08 g of hydrogen and 0.64 g of oxygen?CH₂OCH₄OC₂H₄O₂C₄H₂OQuestion 8 of 9 Loading... 9. What is meant by the term empirical formula?A chemical formula that shows the actual numbers of the different types of atoms in a moleculeBaby food for emperorsA method of calculating the ratios of masses in an equationA chemical formula that shows the simplest ratio of the numbers of atoms in a compoundQuestion 9 of 9 Loading... Related Posts:The entire quiz question bank!The entire quiz question bank (Double only)!Key Calculations quizEquilibria (triple) quizCondensation Polymers quizElectrolysis quiz Hydr0Gen2020-02-16T16:38:53+00:00Categories: Uncategorized|Tags: Quiz, Topic: Calculations| Share This Story, Choose Your Platform! FacebookXRedditLinkedInTumblrPinterestVkEmail