Moles He = 7.83 x 10^24 / 6.02 x 10^23 =13.0
<span>mass He = 13.0 mol x 4.00 g/mol = 52.0 g</span>
Answer:
The molecular formula of estradiol is: 
.
Explanation:
Molar mass of of estradiol = M= 272.37 g/mol
Let the molecular formula of estradiol be 
Percentage of an element in a compound:
Percentage of carbon in estradiol :
x = 18.0
Percentage of hydrogen in estradiol :
y = 24.2 ≈ 24
Percentage of oxygen in estradiol :
z = 2
The molecular formula of estradiol is: 
Answer:
D
Explanation:
According to this question, each model of molecules in the options contains spheres of different colors and sizes representing different types of atoms. The atoms of the same element are the spheres of same color and size while atoms of different element are of different color or size.
Therefore, the model showing a molecule of a substance that is made up of three elements is model D because it is made up of three distinct spheres representing atoms of each element.
- The red sphere is the atom of the first element
- The big dark sphere is the atom of the second element
- The small white sphere is the atom of the third element
Answer:
The mole fraction of ethanol is 0.6. A 10 mL volumetric pipette must be used for to measure the 10 mL of ethanol. The vessel should be clean and purged.
Explanation:
For calculating mole fraction of ethanol, the amount of moles ethanol must be calculated. Using ethanol density (0.778 g/mL), 10 mL of ethanol equals to 7.89 g of ethanol and in turn 0.17 moles of ethanol. The same way for calculate the amount of water moles (ethanol density=0.997 g/mL). 2 mL of water correspond to 0.11. The total moles are: 0.17+0.11=0.28. Mole fraction alcohol is: 0.17/0.28=0.6
1 mole of N2 produces 2 moles of NH3
OR...
14 x 2 grams of N2 produces 2(14 +3) grams of NH3
1 gram of N2 produces 34/28 grams of NH3
therefore, 56 grams produce (34/28 )x 56 =68 grams of NH3
the answer thus would be 68 grams of NH3
