## 26.How many atoms of oxygen are represented in 3Ba(ClO3)2? A.3 B.6 C.9 D.18 27.How many atoms of o

Question

26.How many atoms of oxygen are represented in 3Ba(ClO3)2?

A.3
B.6
C.9
D.18

27.How many atoms of oxygen are represented in 3Fe(NO3)2?

A.3
B.6
C.12
D.18

28.When the following equation is balanced with the lowest whole number coefficients possible, what is the coefficient in front of H2O?

Fe (s) + H2O (g) Fe3O4 (s) + H2 (g)
A.2
B.4
C.6
D.8

29.Which chemical equation below is balanced correctly?

A.2H2O H2 + O2
B.CH4 + 3O2 CO2 + 2H2O
C.Al4C3 + 3H2O CH4 + 4Al(OH)3
D.Zn + 2HCl ZnCl2 + H2

30.When the following equation is balanced with the lowest whole number coefficients possible, what is the coefficient in front of HNO3?
N2O5 + H2O HNO3

A.1
B.2
C.4
D.5

31.How many atoms of hydrogen are represented in 2CH3CH2O?

A.5
B.6
C.7
D.10

32.How many moles of oxygen gas would be needed to react completely with 8 moles of lithium metal in the following reaction?
4Li + O2 2Li2O

A.1
B.3
C.2
D.6

33.When 4.5 mol Al react with 11.5 mol HCl, what is the limiting reactant, and how many moles of H2 can be formed?
2Al + 6HCl → 2AlCl3 + 3H2

A.Al is the limiting reactant; 4.5 mol H2 can be formed
B.HCl is the limiting reactant; 3.8 mol H2 can be formed
C.Al is the limiting reactant; 6.8 mol H2 can be formed
D.HCl is the limiting reactant; 5.8 mol H2 can be formed

34.If 38.7 grams of lithium chlorate decomposes, how many grams of oxygen gas can be produced?
2LiClO3 → 2LiCl + 3O2

A.41.1 g O2
B.20.6 g O2
C.9.13 g O2
D.6.85 g O2

35.For the reaction shown, 38.25 grams of silicon is combined with 14.33 grams of nitrogen gas. How many grams of silicon nitride can be formed if nitrogen is the limiting reactant?
3Si + 2N2 Si3N4

A.17.94 g
B.21.23 g
C.35.88 g
D.63.69 g

36.If 62.4 grams of white phosphorus react with 136.2 grams of chlorine, how many grams of phosphorus trichloride can be formed?
P4 + 6Cl2 4PCl3

A.137 g
B.176 g
C.263 g
D.277 g

37.Which of the following is true of physical properties?

A.Physical properties include properties like mass, color, and flammability.
B.Physical properties cannot be observed without changing the identity of the material.
C.Physical properties include properties like density, melting point, and ductility.
D.Physical properties describe the potential for the material to undergo a reaction.

38.What coefficients must be added to balance the following equation?
_____NaOH + _____H2 SO4 _____ Na2SO4 + _____ H2O

A.2, 1, 1, 1
B.3, 1, 1, 3
C.2, 1, 1, 2
D.4, 2, 2, 1

39.Which of the following chemical equations violates the law of conservation of mass?

A.K2SO4 + 2Ca(NO3)2 2KNO3 + 2CaSO4
B.Ti + 2Cl2 TiCl4
C.2C2H2 + 5O2 4CO2 + 2H2O
D.BaSO4 + 2NaOH Ba(OH)2 + Na2SO4

40.Which of the following is a double replacement reaction?

A.K2S + CoCl2 2KCl + CoS
B.Ca + 2H2O Ca(OH)2 + H2
C.CaO + H2O Ca(OH)2
D.2KClO3 2KCl + 3O2

41.Which of the following statements is true of combustion reactions?

A.Hydrogen gas (H2) must be one of the reactants
B.Water (H2O) is always a product
C.Energy is released by the reaction
D.Carbon monoxide (CO2) is always produced

42.Using the balanced equation below, how many moles of calcium chloride are needed to react completely with 4.3 moles of silver nitrate?
2AgNO3 + CaCl2 2AgCl + Ca(NO3)2

A.1.4 mol CaCl2
B.2.2 mol CaCl2
C.4.3 mol CaCl2
D.8.6 mol CaCl2

43.When 3.5 mol Al react with 12.5 mol HCl, what is the limiting reactant and how many moles of H2 can be formed?
2 Al + 6 HCl 2 AlCl3 + 3 H2

A.Al is the limiting reactant; 3.5 mol H2 can be formed
B.HCl is the limiting reactant; 3.2 mol H2 can be formed
C.Al is the limiting reactant; 5.3 mol H2 can be formed
D.HCl is the limiting reactant; 6.3 mol H2 can be formed

44.How many moles of H2O can be formed when 4.5 moles of NH3 react with 3.2 moles of O2?
4NH3 + 5O2 4NO + 6H2O

A.3.8 mol H2O
B.4.8 mol H2O
C.6.4 mol H2O
D.6.8 mol H2O

45.If the reaction of 3.50 moles of lithium with excess hydrofluoric acid was able to produce 1.32 mol H2, what is the precent yield of the reaction?
Unbalanced equation: Li + HF LiF + H2

A.75.4%
B.37.7%
C.18.9%
D.13.3%

in progress 0

1. Que26

The number of oxygen atoms 18 atoms of oxygen ( answer D)

calculation

count the number of oxygen atoms in Ba(ClO3)2

that is = 3 x2 = 6 atoms

then multiply by 3 since there are 3 molecules of Ba(ClO3)2

that = 6 x3 = 18 atoms of oxygen

Que 27

The number of atoms of oxygen is 18 atoms of Oxygen ( answer D)

calculation

Step 1: count the number of oxygen atoms in Fe(NO3)2

that is = 3 x2 = 6 atoms of Oxygen

Step 2: multiply by total number of Fe(NO3)2 molecules ( 3 molecules)

that is , 6 x3 = 18 atoms of oxygen

question 28

The coefficient in front of H2O is 4 ( answer 8)

Explanation

Balance the equation

= 3 Fe + 4 H2O u2192 Fe3O4 + 4 H2

therefore the coefficient in front of H2O = 4

que 29

The balance chemical equation is

Zn + 2HClu2192 ZnCl2 +H2 ( answer D)

Explanation

Zn + 2HClu2192 ZnCl2 + H2 is balanced since it obey the law of mass conservation.

Que 30

The coefficient in front of HNO3 is 2 ( answer B)

Explanation

balance the equation of N2O5 + H2Ou2192 2HNO3

Therefore the coefficient in front of HNO3 is 2

Que 31

The number of atoms of Hydrogen is 10 atoms ( answer D)

Calculation

Step 1: count the number of H atoms in CH3CH2O

= 3 +2= 5 atoms

Step 2: multiply 5 atoms by 2 ( coefficient in front of CH3CH2O)

= 5 atoms x 2 = 10 atoms

Ques 32

The moles of Oxygen gas needed is 2 moles ( answer C)

Explanation

= 4 Li +O2 u2192 2Li2O

The mole ratio of Li :O2 = 4:1

therefore the moles of Oxygen = 8 moles x1/4 = 2 moles

Que 33

The limiting reactant is HCl and 5.8 moles of H2 can be formed

Explanation

to determine the limiting reagent

Al : AlCl3 is 2 :2 = 1:1 therefore the moles of AlCl3 = 4.5 moles

HCl: AlCl3 = 6:2 therefore the moles of Al2Cl3 = 11.5 x2/6= 3.8 moles

therefore HCl is the limiting reagent since it is totally consumed

moles of HCl formed

The mole ratio of HCl: H2 = 6:3 therefore the moles of H2 = 11.5 x 3/6 = 5.8 moles

que 34

The grams of oxygen gas = 20.6 g O2( answer A)

explanation

calculate the moles of LiClO3

= 38.7 g / 90.38 g/mol=0.428 moles

by use of mole ratio of of LiClO3: O2= 2:3 the moles of O2

= 0.428 x3/2=0.642 moles

mass =moles x molar mass

= 0.642 moles x 32 g/mol= 20.6 g O2

Ques 35

The grams of silicon nitride that can be formed is 35.88 g( answer C)

calculation

find the moles of nitrogen

= 14.33 g/ 28 g/mol=0.512 moles

N2: Si3N4 is 2:1 the moles of SiN4

= 0.512 moles x 1/2=0.256 moles

find the grams of Si3N4

= 0.256 moles x 140.28 g/mol = 35.91 g which is around 35.88 (answer c)

Que 36

The grams of phosphorus trichloride that can be formed is is 176 g ( answerB)

calculation

tmoles of P4 = 62.4 g / 123.90 g/mol =0.504 moles

tmoles of cl2 = 136.2/71 g/mol =1.918 moles

P4 : PCl3 is 1:4 therefore the moles of PCl3 = 0.504 x 4=2.016 moles

Cl2 : PCl3 is 6:4 therefore the moles of PCl3= 1.918 moles x 4/6=1.279 moles

Cl2 is the limiting reagent therefore the moles of PCl3 = 1.279 moles

find the mass of PCl3

= 1.279 moles x 137.33 g/mol =176 g

Que 37

The truth about physical properties is The physical properties include properties like density, melting point, and ductility

Explanation

Physical properties are be measure or observed without changing the composition of matter.

Que 38

The coefficient that must be added to balance the equation are

Explanation

The mass of the product is equal to mass of the reactant when the equation is balanced..

que 39

The chemical equation that violates the law of mass conservation of mass is K2SO4 +2Ca(NO3)2u2192 2KNO3 + 2CaSO4 ( answer A)

Explanation.

K2SO4 + 2Ca(NO3)2 u2192 2KNO3 + 2CaSO4 violate this law because the mass of reactant is not equal to mass of product.

For example in )2 there is 16 atoms of aO2 in reactant side while at product side they are 14 atoms.

Que 40

The double replacement reaction is

K2S + CoCl2u2192 2KCl + COS ( answer A)

Explanation

in Double replacement the cation and anion of the two reactant switch places to form new compound.

## NB: find question 41- 45 in the attachment below ( the answer was long could not all fit.)

2. please check the only final answers here below and, please find attached file of word document which has the full and complete answers and explanations to all parts of your question.

26- the correct answer is ( D )18

27- the correct answer is D 18 atoms
28-the correct answer is B 4

29- the correct answer is D Zn + 2HClu2192ZnCl2 + H2

30-u2234 the correct answer is B 2

31- the correct answer is D 10

33- the correct answer is D HCl is the limiting reactant, 5.8 mol of H2 can be formed

34- the correct answer is B 20.6 g

35- the correct answer is C 35.88 g

36-the correct answer is D 277 g

37- the correct answer is C

38- the correct answer is C 2,1,1,2

39- the correct answer is A) K2SO4 + 2 Ca(NO3)2u21922KNO3 + 2CaSO4

40- The correct answer is (A ) K2S + COCl2u21922 KCl + COS

41- the correct answer is (B) water (H2O) is always a product

42- the correct answer is B 2.2 mol

43- the correct answer is (C) Al is the limiting reactant, 5.3 moles of H2 can be formed

44- the correct answer is (D ) 6.8 moles

45-the correct answer is A 75.4 %