emeraldbeauty

Can someone help me on this question please?

After a one year storage period, an aqueous drug solution with an initial concentration of 5% (w/v) was shown by analysis to have a concentration of 45 g L-1. The drug solution is known to be ineffective if it decomposes to 70% of the initial concentration.

Assuming first order kinetics of decomposition (C = C0e-kt), calculate the shelf life (in months) of the drug solution.

Please give the answer rounded to 1 d.p.

Thank you :)

How many cubic millimetres (mm) are in a cubic nanometre (nm)?

Express your answer as an index (such as: 10^99)

Q2) 3.0 × 1012 mm3 = into km3

express answer in index form

How do I do these questions? Help please? Thank you

You have a 5 M HCl solution.

What is the concentration of HCl in mg mL-1?

Note: H = 1g mol-1; Cl = 35.5 g mol-1

im going to take chemistry, biology, english lit &lang. and maths for A-levels.

im just thinking about what i would do in University. but im really confused, and just lost. i have no real definite thing i want to get into. im a little worried because i have to make decisions soon.

im thinking medicine, forensic science, something in the science field.

what do you think i could do with these subjects??? (courses in uni and jobs in the future)

anything, it doesn't have to be in the science field, but that is what i would prefer, as i am strong in that subject.

please help....Thanks in advance

your suggestions would really help me, decide and get things straight.

thanks again :)