Ch (2) : Calculations With Chemical Formulas And Equations

15 Questions | By Alnagar | Last updated: Mar 18, 2022 | Total Attempts: 267

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Ch (2) : Calculations With Chemical Formulas And Equations - Quiz

QUIZ FOR (( calculations with chemical formulas and equations )) Faculty of Engineering, Zagazig University BY &

Questions and Answers

1.

Percentage of Magnesium [Mg] in Magnesium sulfate [MgSO₄] Given Atomic Weights: Mg = 24 . S = 32 . O = 16
- A.
  
  40
- B.
  
  20
- C.
  
  12
- D.
  
  60
2.

Balance the following equation: Mg₃N₂ + H₂O Mg(OH)₂ + NH₃
- A.
  
  Mg3N2 + 6H2O --> 3Mg(OH)2 + 2NH3
- B.
  
  Mg3N2 + 6H2O --> 3Mg(OH)2 + NH3
- C.
  
  Mg3N2 + 2H2O --> Mg(OH)2 + NH3
- D.
  
  Mg3N2 + 3H2O --> 3Mg(OH)2 + 2NH3
3.

Calculate the mass % of carbon in carbon monoxide.
4.

A reaction that produces crude iron from iron ore is shown below: Fe₂O₃ (s) + 3CO (g) 2Fe (s) + 3CO₂ (g) How many moles of iron could be produced from the reaction of 10 mol Fe₂O₃ and 25 mol of CO?
- A.
  
  10 mol
- B.
  
  25 mol
- C.
  
  17 mol
- D.
  
  20 mol
- E.
  
  35 mol
5.

You are given the following percentages: 40.05% S and 59.95% O. Find the empirical formula for these elements
- A.
  
  SO
- B.
  
  SO2
- C.
  
  SO4
- D.
  
  SO3
6.

Given the following: 42.07% Na, 18.89% P, and 39.04% O, determine the empirical formula
- A.
  
  NaPO2
- B.
  
  Na2PO3
- C.
  
  Na3PO4
- D.
  
  NaPO4
7.

Styrene has the empirical formula CH, and there is 92.25% carbon and 7.75% hydrogen. If you have a molar mass of 104g/mol, what is the multiplier or factor to get the molecular formula?
- A.
  
  6
- B.
  
  2
- C.
  
  4
- D.
  
  8
8.

Al(OH)3 + 3HCl --> 3H2O + AlCl3 If you have 14.0 grams of aluminum hydroxide, how much aluminum chloride is produced?
- A.
  
  14.0 g
- B.
  
  17.9 g
- C.
  
  23.9 g
9.

Al(OH)3 + 3HCl --> 3H2O + AlCl3 If you actually recovered 22.0 grams of aluminum chloride, what is the percent yield of the reaction?
- A.
  
  100%
- B.
  
  92%
- C.
  
  69%
10.

What is the percentage of oxygen in carbon dioxide? (CO2)
11.

Empirical Formula: 39.8% K, 27.8% Mn, 32.5% O
- A.
  
  N3,Mn,5O
- B.
  
  K2,Mn,O4
- C.
  
  Mn3,K,O7
- D.
  
  O10,Mn,5K
12.

The simplest formula of a substance shows
- A.
  
  the actual number of atoms of each element in one molecule of a substance.
- B.
  
  the elements that make up one molecule of the substance and the simplest whole number ratio between the atoms.
- C.
  
  the number of molecules in a sample of the substance.
- D.
  
  the molecular mass of the substance.
13.

A compound is found to have a molecular mass of 90 atomic mass units and simplest formula of C₂H₅O. The molecular formula of the substance is: (Atomic mass of C = 12 amu, H = 1 amu, O = 16 amu)
- A.
  
  C3H6O3
- B.
  
  C4H26O
- C.
  
  C4H10O2
- D.
  
  C5H14O
14.

How many grams of oxygen are in one mole of calcium carbonate, CaCO₃? (Atomic mass of O = 16 amu.)
- A.
  
  16 grams
- B.
  
  32 grams
- C.
  
  48 grams
- D.
  
  64 grams
15.

The ionic compound containing Fe³⁺ and SO₄^2- would have the formula
- A.
  
  FeSO4
- B.
  
  Fe2SO4
- C.
  
  Fe2(SO4)3
- D.
  
  Fe3(SO4)2