Is answer correct or not? (about chemical calculation)

Question

Calculate the number of moles of oxalic acid and the molarity of the oxalic acid solution.

 Molar mass of H2C2O4•2H2O 126.07 g/mol

 Mass of H2C2O4•2H2O              1.5232g

 1) No. of moles of H2C2O4•2H2O _______?________ mol

 Volume of H2C2O4•2H2O solution          250.0  mL   

 2) Molarity H2C2O4 standard solution      _____?____M

1) Answer is 1.5232 x 1 mol /126.07 g/mol = 0.012082 mol

2) Answer is 0.012082 / 0.25L = 0.048328 M

I didn't exactly understand the "standard solution" What is mean?

My answer is correct or not?

and sometimes, I don't know how many decimal places I have to write down. How to write the answer correctly form?

Answer 1

1) moles 1.5232 g x 1 mol/126.07 g = 0.012082 moles (5 s.f.)

2) 0.0120822 moles/0.2500 L = 0.04833 M (4 s.f.)

Yes, your answer is correct.