How many moles of hydrogen and oxygen are in 2 moles of water?

water: h2o
# of molecules = (6.022 x 10^23)(2)= 1.2044 x 10^23
# of hydrogen atoms = (1.2044 x 10^23)(2)= 2.4088 x 10^24
# of oxygen atoms = 1.2044 x 10^24

Did I do this correctly? What do I do about significant digits since the number 2 for 2 mol is only one significant digit?

No, you calculated the number of atoms in the molecule. The question is for moles. There are two moles of hydrogen per mole of H2O and one mole 0f oxygen per mole of H2O. Therefore, for 2 moles of H2O, there are 4 moles of hydrogen and 2 moles of oxygen.

Thank you :)

If I would have had something like 2.4 would I round it to 2 because of significant digits?

No, if you had 2.4 moles instead of 2.0, it would then be (for H) 2 x 2.4 = 4.8. In multiplication you are allowed the number of significant figures for the least significant number used. Since 2.4 has 2 s.f. and 2 moles H2O (I assume that would mean 2.000000000), then you would be allowed 2 s.f. and 2.0 x 2.4 = 4.8 moles. (5 moles as an answer would be incorrect as would be 4.80.)

Yes, you have correctly calculated the number of hydrogen and oxygen atoms in 2 moles of water. However, you mentioned that the number 2 for 2 moles of water has only one significant digit. In scientific notation, the coefficient (number) is usually written with all significant digits, and the exponent (power of 10) represents the precision of the measurement.

In this case, since the value given is "2 moles," you should assume that it has an implied uncertainty of +/- 0.5 moles. As a result, the number of significant digits in your answer should match the number of significant digits in the input value.

Hence, when multiplying by Avogadro's number (6.022 x 10^23), you should write the result as 1.2044 x 10^24, while considering the significant digits from the original input value.

If you want to account for significant digits, you could round your final answer to the appropriate number of significant figures. For example, if you are working with one significant figure (2 moles), your final answer would be 1.2 x 10^24 atoms of hydrogen and 1.2 x 10^24 atoms of oxygen.