An experiment requires you to create a stock buffer containing 0.15 M of NaCl in a total volume of 200 mL.

How many grams (g) of solid NaCl are required to prepare this stock solution?

Note: Your answer should be to two decimal places, e.g. 4.31

6 mL of a stock solution of 300 mM citrate buffer is diluted to a final volume of 30 mL.

What is the final concentration of the diluted citrate buffer (in units of mM)?

You took 2 mL of a stock solution of sodium phosphate (60 mM) and mixed it with 8 mL of water to make solution A.

You then took 1 mL of a solution A and mixed it with 3 mL of water to make solution B. 

You then took 2 mL of a solution B and mixed it with 2 mL of water to make solution C.

Calculate the concentration (in mM) of sodium phosphate in each of these solutions.

A sample contains 70 μg of NaOH.

How many milligrams (mg) is this?

An experiment requires the use of 5 mmol of monopotassium phosphate, which has a molecular mass of 136 Da.

What mass of monopotassium phosphate (in grams, to two decimal places) is needed for this experiment?

A patient has been admitted to hospital and a blood test has shown his glucose level is 40 mg per 60 mL.

Calculate the molarity (in mM, to two decimal places) of the glucose in the patient's blood.

Choose the best option to complete the following statement.

In the process of RNA synthesis, the problem of ensuring the correct sequence is made is solved by:

Compare the two DNA duplexes shown below.

Duplex 1                  Duplex 2

5′-ACCGAGTCCG-3′          5′-ATAACTATGT-3′

3′-TGGCTCAGGC-5′          3′-TATTGATACA-5′

Which of the following statement(s) is/are correct?

The following sequence of RNA forms a “hairpin” structure.

5′-UCGUGUGCUGCACCACAGCACAAUGCU-3′

What will be the effect on the stability of this hairpin structure if the bold, underlined nucleotide is mutated from G to U?

The following sequence of RNA forms a “hairpin” structure. The duplex region contains all Watson-Crick base pairs without any gaps or mismatches.

5′-CGUAUACUAGACUGCUGGUCUAGUUACU-3′

In the space below, type the sequence of either of the two regions that form a duplex with each other.

Be careful not to type any spaces or additional characters. For example, if you think the answer is 5'-AGCC-3', simply type AGCC.