1st year Biochemistry help!

I'm really struggling with the basic chemistry here as, can anyone give me a hand?


The following is a recipe for the reaction mixture for a PCR amplification of DNA.
In a total volume of 50µl, add the following:
2µl template DNA (10ng - 500ng)
5µl 10x Taq DNA polymerase buffer with MgCl2
1µl dNTP mixture (10mM each nucleotide: dATP, dCTP, dGTP, dTTP)
2.5µl Forward primer (10µM stock)
2.5µl Reverse primer (10µM stock)
0.2µl Taq DNA polymerase (5 units / µl)
Water to 50µl

(d) How much of each primer (in moles) is added to the reaction? How much
nucleotides (sum of all four; in moles) is present in the reaction mixture?
(Note. You may want to look up details of the process occurring here to see why
nucleotides are present in large excess over primers.)
(e) If 10ng of a double stranded DNA sequence, length 900 base pairs, is used as
template, how much (moles) is present in the reaction mixture? (Assume 1 base pair
has a "molecular weight" of 625.) How many molecules is this (Avogadro's number =
6.022 x 1023)?



These are the two question im struggling with right now can anyone give me a hand ?