Answer:
D. the mass of one mole of a substance
Explanation:
The molar mass of a substance is the mass in grams of one mole of the substance.
- For an element, the molar mass is the relative atoms mass expressed in grams.
- For example 23g of Na, 40g of oxygen
- For compounds, molar mass is the gram -formula or gram - molecular weight.
- This is determined by the addition of its component atomic masses and then expressed in grams.
Answer:
23.34 %.
Explanation:
- The percentage of water must be calculated as a mass percent.
- We need to find the mass of water, and the total mass in one mole of the compound. For that we need to use the atomic masses of each element and take in consideration the number of atoms of each element in the formula unit.
- <em>Atomic masses of the elements:</em>
Cd: 112.411 g/mol, N: 14.0067 g/mol, O: 15.999 g/mol, and H: 1.008 g/mol.
- <em>Mass of the formula unit:</em>
Cd(NO₃)₂•4H₂O
mass of the formula unit = (At. mass of Cd) + 2(At. mass of N) + 10(At. mass of O) + 8(At. mass of H) = (112.411 g/mol) + 2(14.0067 g/mol) + 10(15.999 g/mol) + 8(1.008 g/mol) = 308.5 g/mol.
- <em> Mass of water in the formula unit:</em>
<em>mass of water</em> = (4 × 2 × 1.008 g/mol) + (4 × 15.999 g/mol) = 72.0 g/mol.
- <em>So, the percent of water in the compound = [mass of water / mass of the formula unit] × 100 = [(72.0 g/mol)/(308.5 g/mol)] × 100 = 23.34 %</em>
Answer:
See explaination
Explanation:
Reaction between p- toluidine and o- vaniline to form imine.This reaction does occur in the presence of a acidic source.
Here the -OH group in the o- vaniline is quite acidic so it acts a internal acidic catalyst. Hence the reaction occurred in the absence of any external acidic source.The reaction mechanism is given at the attached file.
please kindly see attachment.
2Al+3Cl2==>2AlCl3
(4mol Al)(2 mol AlCl3/2 mol Al)=4 mole AlCl3
