Explanation:
<u>Moles is denoted by given mass divided by the molecular mass , </u>
Hence ,
n = w / m
n = moles ,
w = given mass ,
m = molecular mass .
For example ,
For a compound X ,
The given mass i.e. w = 20 g
and the molecular mass ,i.e. , m = 10 g / mol
Then the moles can easily be calculated by using the above formula ,
n = w / m
n = 20 g / 10 g/mol = 2 mol
Hence , answer = 2 mol.
Earth's atmosphere is 78% nitrogen, 21% oxygen, 0.9% argon, and 0.03% carbon dioxide with very small percentages of other elements. Our atmosphere also contains water vapor. In addition, Earth's atmosphere contains traces of dust particles, pollen, plant grains and other solid particles.
T cells and B cells are similar because they both deal with fighting of viruses.
Answer:
36290 min = 604.8 hr.
Explanation:
1 lbs = 453.59237 grams.
∴ 2 lbs = 907.18474 grams.
<em><u>Using cross multiplication:</u></em>
500 mg of iron oxide dissolved → 20 minutes.
907184.74 mg of iron oxide dissolved → ??? minutes.
<em>∴ The time needed to dissolve 2 lbs of iron oxide =</em> (907184.74 mg)(20 min)/(500 mg) = <em>36290 min = 604.8 hr.</em>