LABORATORY MATHEMATICS

Question 1

Measurement: Length
Name: Meter
Symbol:

Answer 1

Measurement: Length
Name: Meter
Symbol: m

Question 2

Measurement: Mass
Name: Kilogram
Symbol:

Answer 2

Measurement: Mass
Name: Kilogram
Symbol: kg

Question 3

Measurement: Quantity of substance
Name:
Symbol:

Answer 3

Measurement: Quantity of substance
Name: Mole
Symbol: mol

Question 4

Measurement: Quantity of substance
Name:
Symbol:

Answer 4

Measurement: Quantity of substance
Name: Second
Symbol: s

Question 5

Measurement: Electric current
Name:
Symbol:

Answer 5

Measurement: Electric current
Name: Ampere
Symbol: A

Question 6

Measurement: Thermodynamic temperature
Name:
Symbol:

Answer 6

Measurement: Thermodynamic temperature
Name: Kelvin
Symbol: K

Question 7

Measurement: Luminous intensity
Name:
Symbol:

Answer 7

Measurement: Luminous intensity
Name: Candela
Symbol: cd

Question 8

Factor: 10^-18
Prefix:
Symbol:

Answer 8

Factor: 10^-18
Prefix: Atto
Symbol: a

Question 9

Factor: 10^-15
Prefix:
Symbol:

Answer 9

Factor: 10^-15
Prefix: Femto
Symbol: f

Question 10

Factor: 10^-12
Prefix:
Symbol:

Answer 10

Factor: 10^-12
Prefix: Pico
Symbol: p

Question 11

Factor: 10^-9
Prefix:
Symbol:

Answer 11

Factor: 10^-9
Prefix: Nano
Symbol: n

Question 12

Factor: 10^-6
Prefix:
Symbol:

Answer 12

Factor: 10^-6
Prefix: Micro
Symbol: u

Question 13

Factor: 10^-3
Prefix:
Symbol:

Answer 13

Factor: 10^-3
Prefix: Milli
Symbol: m

Question 14

Factor: 10^-2
Prefix:
Symbol:

Answer 14

Factor: 10^-2
Prefix: centi
Symbol: c

Question 15

Factor: 10^-1
Prefix:
Symbol:

Answer 15

Factor: 10^-1
Prefix: Deci
Symbol: d

Question 16

Convert 3 uL to L

Answer 16

3x10^-6 L or
0.000003 L

Question 17

Percent concentrations formula:
1. w/v % solutions:
2. v/v % solutions:
3. w/w % solutions:

Answer 17

1. w/v % solutions:
   % (w/v) = weight of solute (g)/total volume of solution (mL) x 100%
2. v/v % solutions:
   % (v/v) = volume of solute (mL)/total volume of solution (mL) x 100%
3. w/w % solutions:
   % (w/w) = weight of solute (g)/total weight of solution (g) x 100%

Question 18

How much sodium chloride should be used to prepare 2 liters of 0.85% (w/v) saline solution?

Answer 18

17 grams

Given:
solute = x
solution = 2 L
concentration = 0.85%

solution:
conc. = solute (g)/solution (mL) x 100 %

0.85 = x/2000 mL x 100%

x = 0.85 x 2000 mL/100

= 17 grams

Question 19

Formula for Molarity:

Answer 19

Molarity (M) = amount of solute (in moles) / total volume of solution (in mL)

Question 20

A registered medical technologist dissolved 100 g of sodium chloride in 5 liters of distilled water. What is the molarity of the resulting solution? (MW: Na = 23 ; Cl = 35.45)

Answer 20

0.34 M

Given:
solute = 100 g —-> moles
solution = 5 L
M = x

Solution:
g —-> moles
100 g/58.45 = 1.71 moles

M = 1.71 moles/5 L
M = 0.34 M

Question 21

Formula for Normality:

Answer 21

Normality (N) = amount of solute (in moles / total volume of solution (in L) x valence

or

N = M x v
(valence = amount of H+ ion)

Question 22

What is the Normality of a 200 mL solution containing 5 grams of H2SO4?
(MW: H = 1; S = 32; O = 16)

Answer 22

0.51 N

Given:
Solute = 5 g
Solution = 200 mL —-> 0.2 L
N = x

Solution:
g —-> moles
5 g/98 = 0.051 moles

N = 0.051 moles/0.2 L x 2
N = 0.51 N

Question 23

What is the final concentration of a 50% solution that was diluted 1:2, 1:5 then 1:10?

Answer 23

0.5%

Final concentration = original concentration /product of all diluting factor

= 50%/2x5x10
= 0.5%

Question 24

temperature conversions:
C to F =

Answer 24

F = (C x 1.8) + 32

Question 25

temperature conversions:
F to C =

Answer 25

C = (F - 32) x 0.556