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

a: 45.9 meters

b: 4.29 seconds

step-by-step explanation:

a: h(t)=1/2(-9.8)(3)^2+0(3)+90

h(t)=-4.9(3)^2+90

h(t)=-44.1+90

h(t)=45.9 meters

b: 0=1/2(-9.8)(t^2)+0t+90

0=-4.9t^2+90

-90=-4.9t^2

18.37=t^2

t=4.29 seconds

in the second question, the numbers aren't exact, but they're a close approximation.