A chemist collects 2.94 L of carbon monoxide
(CO) gas at STP during an experiment. Explain
how she can determine the mass of gas that she
collected. Why is the mole important for this
calculation?

3.68g

Explanation:

The mole is central to all chemical calculations in quantitative chemistry. Without the mole, we cannot truly and accurately measure out a specified amount of substance or predict the quantity of the product likely to be obtained.

A mole is the number of substance that contains the Avogadro's number of particles.

To determine the mass of gas;

                  Mass = number of moles x molar mass

  the mass can be determine;

 At stp;

      1 mole of any gas occupied a volume of 22.4L

      x mole of CO gas will occupy a volume of 2.94L

         22.4x = 2.94

               x = = 0.13mole

    Now to find the mass;

      Molar mass of CO = 12 + 16 = 28g/mole

     Mass = 0.13 x 28 = 3.68g

there all right good

explanation:

2fe + 3h2so4 -> fe2(so4)3 + 3h2

it is necessary to balance equations in order to get the proper amount of reactants as well as products in order not to make a miscalculation.

you cannot change the subscripts as that would change the substance itself. for instance, diatomic elements such as h2 only have the subscript two when a gas. another example would be so4, if you were to change the subscript, the element would no longer be sulfate.

we change the coefficients instead as that only changes the number of molecules rather than the substance itself.

hope this !