Study text: "Essential Mathematics and Statistics for Science", 2nd Edition,

G Currell & A A Dowman, Wiley-Blackwell, 2009

G Currell & A A Dowman, Wiley-Blackwell, 2009

- The numerical value for the focal length,
*f*, of a particular lens is given by the equation:

1/*f*= 1/20 + 1/30

Calculate the value of*f*- 12
- 24
- 25
- 50

- A particular butterfly spent one quarter of its life (after the egg stage) as a caterpillar, and then two thirds of its life as a pupa before the final stage of being an adult butterfly. What fraction of its life did it spend as an adult butterfly?
- 2/7
- 3/7
- 11/12
- 1/12

- The pressure,
*p*, of a fixed amount of an ideal gas at constant volume is proportional to the absolute temperature,*T*.

A specific quantity of gas has an initial pressure of 570 kPa at a temperature of 285 K, and the temperature is then increased to 300 K.

Calculate (to 2 dp) the percentage increase in pressure.- 5.00%
- 5.26%
- 10.00%
- 10.53%

- The theoretical yield for a particular chemical reaction was calculated as 5.20 g, but the actual reaction produced a yield of 3.76 g.

Calculate (to 3 sf) the percentage yield.- 38.3 %
- 138 %
- 72.3 %
- 86.0%

- Which of the following experimental values shows the lowest relative (or fractional) error?
- 0.076 with an error of 0.001
- 5.62×10
^{-3}with an error of 9.6×10^{-5} - 13.6 with an error of 1.5%
- 3.6 with an error of 0.04

- The element chlorine has two main isotopes,
^{35}Cl and^{37}Cl, of relative masses 35.0 and 37.0 respectively.

Assuming that 75% of naturally occurring chlorine atoms are the^{35}Cl isotope and 25% are the^{37}Cl isotope, calculate the 'average' value for the relative atomic mass.- 36.5
- 35.7
- 35.5
- 35.25