Calculations Flashcards

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1
Q

Using the rules of significant figures calculate the following: 14.8903 - 2.14

A

12.75

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2
Q

Using the rules of significant figures calculate the following: 6.167 + 70

A

76

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3
Q

Convert 20 degrees F to C

A

-6.67 C

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4
Q

Convert -27.5 degrees C to F

A

-17.5 F

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5
Q

Convert 23 degrees C to K

A

296 K

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6
Q

The density of an object that has a mass of 2.50 g and occupies a volume of 1.20 mL equals

A

2.08 g/mL

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7
Q

Calculate the mass of a rectangular solid that has a density of 2.53 g/cm3 and which measures 2.50 cm by 1.80 cm by 3.00 cm

A

34.2 grams

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8
Q

Find the volume of an object that has a density of 3.14 g/mL and a mass of 93.5 g

A

29.8 mL

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9
Q

A chunk of sulfur has a volume of 7.73 cm3. What is the mass of this sulfur? (density of sulfur = 2.07 g/cm3

A

16 grams

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10
Q

Draw the lewis structure for the chlorine atom

A

Cl with 2 dots on three sides and 1 dot on 1 side

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11
Q

Draw the Lewis structure for the OH- ion

A

Brackets containing O with 2 dots on three sides and a line to H with no dots. Negative sign outside of brackets

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12
Q

How many moles of 12C are there in a 3.50 gram sample of this substance?

A

0.292 mol

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13
Q

The Atomic weight of helium is 4.0026. What is the mass of a helium sample which contains .427 moles of He gas?

A

1.71 grams

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14
Q

The atomic weight of aluminum is 26.982. How many aluminum atoms are there in a 4.55 g sample of aluminum?

A

1.02 x 10 to 23

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15
Q

The formula mass of (NH4)2SO4 is

A

132.14

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16
Q

A gas sample contains 16.0 grams of CH4, 16.0 grams O2, 16.0 grams SO2 and 33.0 grams of CO2. The total number of moles of everything is

A

2.50 Mol

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17
Q

When the chemical equation BaCl2 + K3PO4 reacts to form KCl + Ba3(PO4)2 is correctly balanced the sum of the smallest set of integer coefficients will be

A

12

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18
Q

Balance this equation C12H22O11 + O2 reacts to form CO2 + H20. How many moles of oxygen are required to react completely with 1.0 mol of sugar?

A

C12H22O11 + 12 O2 reacts to form 12CO2 + 11H2O creating a 1 to 12 ratio of sugar to oxygen so 12 moles sugar are needed for 1 mole of oxygen.

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19
Q

A 3.0 Mole sample of KClO3 was decomposed according the equation 2KCLO3 reacts to form 2KCl + 3O2 How many moles of O2 are formed assuming 100% yield?

A

4.5 moles of O2

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20
Q

For the reaction C2H4 + 3O2 reacts to form 2CO2 + 2H2O if 6.0 Mole of CO2 were produced, how many moles of O2 were reacted?

A

9 Moles O2

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21
Q

Fe3O4 + 4 CO reacts to form 4 CO2 + 3Fe If 201 grams Fe3O4 is reacted with excess CO, what mass of CO2 will be produced?

A

153 grams CO2

22
Q

2S + 3O2 reacts to form 2SO3 If 6.3 grams of S is reacted with 10.0 grams of O2 show by calculation which one will be the limiting reactant

A

Sulfur

23
Q

A gas has a volume of 2.60 liters at a temperature of 87C and a pressure of 1.30 atm. What is the volume of the gas, in liters, at a temperature of 367C and a pressure of 4.70 atm?

A

1.28 L

24
Q

A sample of a gas in a cylindrical chamber with a movable piston occupied a volume of 6.414 liters when the pressure was 850 torr and the temp was 27.2 C. The pressure was readjusted to 5.82 atm by moving the piston. What was the volume occupied by the sample under the later conditions if the temp remained constant?

A

1.23 L

25
Q

A gas sample occupies volume of 18.86 liters when the temperature is 35.2 C and the pressure is 735.5 torr. How many mole of gas are there in the sample?

A

.7214 moles

26
Q

A gas sample occupies a volume of 1.662 liters when the temperature is 150C and the pressure is 842 torr. How many molecules are there in the sample?

A

3.194 x 10 to 22

27
Q

2Cl2 + 4NaOH reacts to form 3NaCl + NaClO2 + 2H2O How many moles of Cl2 are needed to react with 14.4 g NaOH?

A

.18 mole Cl2

28
Q

What is the volume, in liters, occupied by 2.12 moles of N2 gas at .745 atm pressure and a temperature of 55 C?

A

76.6 L

29
Q

Calculate the concentration in %(m/m) of a solution containing 20.5 g of LiF dissolved in 340 g of H2O

A

5.69% (m/m)

30
Q

Calculate the grams of NaOH present in 9.0 mL of an 8.0% (m/v) NaOH solution

A

.72 grams

31
Q

A solution is made by dissolving .35 mole of LiI in enough water to give a final volume of 260.0 mL. What is the molarity of the solution?

A

1.3 M

32
Q

What is the molarity of a solution containing 16.7 grams of NH3 in 1.50 liters of solution?

A

.653 M

33
Q

A .300 M solution of LiOH that contains .500 mole of solute would have a volume, in mL, of?

A

1.67 x 10 to 3 mL

34
Q

What volume, in mL, of 4.0 M NaOH is needed to prepare 145 mL of .15 M NaOH by dilution?

A

5.4 mL

35
Q

If 145 mL of 2.00 M KOH is diluted to 1.15 L, the resulting solution contains how many moles of KOH?

A

.290 moles of KOH

36
Q

Calculate the mass of silver nitrate, in grams, in a 145 mL solution of 4.31 M silver nitrate

A

?

37
Q

The oxidation numbers for the elements in the compound LiAsO3

A

+1 Li, +5 As, -2 O

38
Q

The oxidation numbers for the elements in the polyatomic ion SO3 to 2- would be

A

+4 S, -2 O

39
Q

Which of the following would be a nonredox decomposition reaction a)2CuO reacts to form 2Cu + O2 b)2KClO3 reacts to form 2KCL + 3O2 c)CaCO3 reacts to form CaO + CO2 d)SO2 + H2O reacts to form H2SO3

A

c)CaCO3 reacts to form CaO + CO2

40
Q

Which element is oxidized in the following redox reaction 2H2S + O2 reacts to form 2H2O + S a)sulfur in H2S b)hydrogen in H2S c)oxygen in O2 d)oxygen in H2O

A

a)sulfur in H2S

41
Q

Which substance functions as a reducing agent in the following redox reaction CH4 + 2O2 reacts to form CO2 + 2H2O a)CH4 b)O2 c)CO2 d)H2O

A

a)CH4

42
Q

What is the change in oxidation number for cobalt in the redox reaction 2Co2O3 + 3C reacts to form 4Co + 3CO2 a)+4 to -4 b)+2 to 0 c)+3 to +4 d)+3 to 0

A

d)+3 to 0

43
Q

In the redox reaction 2MnBr3 + SnBr2 reacts to form 2MnBr2 + SnBr4 a)SnBr2 is the oxidizing agent b)MnBr3 is the substance oxidized c)Sn undergoes an oxidation number change of two units d)Mn undergoes an oxidation number change of six units

A

c)Sn undergoes an oxidation number change of two units

44
Q

In which of the following compounds does Cl have an oxidation number of +5 a)HClO b)KClO2 c)Ca(ClO3)2 d)more than one correct response e)no correct response

A

c)Ca(ClO3)2

45
Q

Redox or noredox Cl2 + NaBr reacts to form NaCl + Br2

A

Redox

46
Q

Redox or nonredox NiS + O2 reacts to form NiO + SO2

A

Redox

47
Q

Redox or nonredox AgNO3 + NH4Br reacts to form AgBr + NH4NO3

A

Nonredox

48
Q

Redox or nonredox HCL + Na2CO3 reacts to form NaCL + H2O + CO2

A

Nonredox

49
Q

What is the oxidation number of each nitrogen atom in (NH4)2SO4?

A

-3

50
Q

In which of the following sequences of sulfur containing ions are the ions arranged in order of decreasing oxidation number for S a)SO3 to 2-, SO4 to 2-, S to 2- b)SO4 to 2-, S2O3 to 2-, S to 2- c)S2O3 to 2-, S2O3 to 2-, SO4 to 2- d)more than one correct response e)no correct response

A

b)SO4 to 2-, S2O3 to 2-, S to 2-

51
Q

Which of the following is a non redox reaction a)CaCO3 reacts to form CAO + CO2 b)2KClO3 reacts to form 2KCL + 3O2 c)SO3 + H2O reacts to form H2SO4 d)more than one correct response e)no correct response

A

d)more than one correct resonse

52
Q

Which of the following aqueous solutions contains the greatest number of ions in solution a)2.0 L of 1.50 M magnesium chloride(MgCl2) b)1.0 L of 3.00 M Sodium Sulfate(Na2SO4) c)2.0 L of 1.50 M sodium phosphate(Na3PO4) d)3.0 L of 1.50 M sodium chloride(NaCl) e)2.0 L of 2.0 M potassium fluoride (KF)

A

c)2.0 L of 1.50 M sodium phosphate Na3PO4