The national institute for occupational safety and health (niosh) sets standards for ccl4 in air at 12.6 mg/m^3 of air (a time average over 40 hr). the ccl4 found in a sample is 4800 ppb. does the sample meet the niosh standard?

No, it doesn't.

Explanation:

To convert ppb to mg/m³ we first need to convert to ppm, by just divide the amount by 1,000, so the concentration in the sample is 4.8 ppm.

mg/m³ = (ppm x molar mass)/molar volume

Using the molar mass in gram and the molar volume in liters, multiplying by the parts per million, we will get the concentration in mg/m³.

Molar mass of C = 12 g/mol; molar mass of Cl = 35.5 g/mol

Molar mass of CCl4 = 12 + 4x35.5 = 154 g/mol

Assuming, 25ºC and 1 atm, the molar volume of an ideal gas is 24.45 L, so:

mg/m³ = (4.8 x 154)/24.45

mg/m³ = 30.2

Which is higher than the limit of 12.6 mg/m³

Sample is greater than the standard (32.96 mg/m³ > 12.6 mg/m³)

Explanation:

Please look at the solution in the attached Word file

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.

each  column  of the  table  is called a group. elements in a group share similar properties. groups are  read  from  top  to  bottom. metal. metalloid. nonmetal. solid. liquid. gas. fe. hg. o.  2. 3. 4. 5. 6. 7. 8. 9.  2. beryllium. 9.012. 4.  sodium. 22.990.  11. 3.  magnesium. 24.305.  12.  potassium. 39.098.  19. 4.  calcium. 40.078.  20. i guess  i