Answer with explanations

Answer the following questions with explanation.

1 Substitute the data into the provided formulae and calculate the answer correct to the appropriate number of significant figures (which you need to determine). a) = 1 2 when b =3.4 10^6 and h = 7.0 10^4

b = when h = 5.0 10-1 , m= 3.2 106 , v= 2.7 10^3

c V = u + at when u = 2.7 10^4 , a = 5, t = 3.0 10^3

2 The ratio of the length of the tail of a mouse to that of the rest of its body is 6:5 and its total length is 132mm. Calculate the length of the tail and the body, expressing your answers in millimetres.

3 An aspirin mixture composed of the three compounds A, B and C in the ratio 7:3:2 has a mass of 2 kg. Calculate the masses of each compound, expressing your answers in kilograms

4 Liquids A and B are mixed in the ratio 2:7 (by volume). What volume of liquid A would be present in 72 mL of the mixed solution?

5 How much salt is weighed to make 2 L of 8% w/v salt brine?

6 How much 10% w/v salt brine is needed to prepare 200 mL of 2% w/v salt brine?

7 If 40 g of NaCl is dissolved in 2 litres of water what is the %w/v of the solution?

8 Convert each of the following

a) 8200 g to g

b 0.000056 km to mm

c 2.9 x 10^9 nL to ML

d) 8.5 m2 to mm2

e) 246 m3 to m3

f) 9.4 x 10-5 L to mm3

8 Calculate the volume of stock solution (10 mg/100mL) required to prepare 20 mL of three standard solutions containing 1, 2 and 5 mg/100mL of tartrazine by dilution of the stock with 2-propanol.

9 In the concentration of ethanol (%v/v), a brandy sample was diluted 1/5. What is the dilution factor?

10 How much 2M NaOH is required to make up 1000mL of a 0.01M NaOH solution?

11 If there were 120 micro-organisms on a pour plate of a 10-2 dilution, how many microorganisms were there per mL of the original sample?