Practise the calculations used every day in pharma QC: %RSD, molarity, dilutions, assay, weight variation, density, control charts and ppm. There are 15 questions. Click an answer to see whether you are right, with the working. Each topic links to a free calculator in our Lab Toolkit.
1.Six assay results are 99.6, 100.4, 99.1, 100.8, 99.9 and 100.2%. What is the %RSD (sample SD, n − 1)?
2.Which Excel function gives the sample standard deviation used for %RSD in QC?
3.9 g of NaCl (molar mass 58.44 g/mol) is dissolved and made up to 1 L. The molarity is about:
4.How much NaOH (molar mass 40.00 g/mol) is needed to prepare 500 mL of 0.1 M solution?
5.What volume of a 1 M stock is needed to prepare 100 mL of a 0.05 M solution?
6.A sample is dissolved in 100 mL, then 5 mL is diluted to 50 mL. What is the total dilution volume?
7.Under Ph. Eur. 2.9.5, what is the permitted deviation for film-coated tablets with an average mass of 300 mg?
8.For hard capsules with an average content mass of 250 mg, the permitted deviation for uniformity of mass is:
9.Standard and sample are prepared at the same nominal concentration with a 100% potency standard. If the sample-to-standard area ratio is 0.990, the assay is about:
10.A pycnometer holds 24.9553 g of water and 30.2091 g of sample at 25 °C. The specific gravity is:
11.Specific gravity and density are numerically different at 25 °C because:
12.Using the WHO n plan (n = 1 + √N), how many containers are sampled from a consignment of 100?
13.On an individuals control chart, the mean is 100.0 and the average moving range is 0.6. The upper control limit is:
14.How many grams of NaCl are in 500 mL of a 0.9% w/v solution?
15.An API contains 10 ppm of an impurity. How much impurity is present in 500 mg of API?