Calculate the following to the correct number of significant figures 0.0041 cm x 2.00 cm x 501 cm

4.1 cm³

Explanation:

When multiplying, the product must have the same number of significant figures as the factor with the least number of significant figures.  0.0041 has two significant figures, 2.00 has three significant figures, and 501 has three significant figures.  The answer will have 2 significant figures.

0.0041 cm  ×  2.00 cm  ×  501 cm  

=  4.1082 cm³

≈  4.1 cm³

n2(g) + 3h2-> 2nh3(g)   this is the balanced equation

note the mole ratio between n2, h2 and nh3.   it is 1 : 3 : 2   this will be important.

moles n2 present = 28.0 g n2 x 1 mole n2/28 g = 1 mole n2 present

moles h2 present = 25.0 g h2 x 1 mole h2/2 g = 12.5 moles h2 present

based on mole ratio, n2 is limiting in this situation because there is more than enough h2 but not enough n2.

moles nh3 that can be produced = 1 mole n2 x 2 moles nh3/mole n2 = 2 moles nh3 can be produced

grams of nh3 that can be produced = 2 moles nh3 x 17 g/mole = 34 grams of nh3 can be produced

note:   the key to this problem is recognizing that n2 is limiting, and therefore limits how much nh3 can be produced.