There are <span>4 1/2 cups of flour in a pound of flour. </span>
Answer:
0.17 moles
Explanation:
In the elements of the periodic table, the atomic mass = molar mass. <u>Ex:</u> Atomic mass of Carbon is 12.01 amu which means molar mass of Carbon is also 12.01g/mol.
In order to find the # of moles in a 12 g sample of NiC-12, we will need to multiply the number of each atom by its molar mass and then add the masses of both Nickel and C-12 found in the periodic table:
- Molar Mass of Ni (Nickel): 58.69 g/mol
- Molar Mass of C (Carbon): 12.01 g/mol
Since there's just one atom of both Carbon and Nickel, we just add up the masses to find the molar mass of the whole compound of NiC-12.
- 58.69 g/mol of Nickel + 12.01 g/mol of Carbon = 70.7 g/mol of NiC-12
There's 12g of NiC-12, which is less than the molar mass of NiC-12, so the number of moles should be less than 1. In order to find the # of moles in NiC-12, we need to do some dimensional analysis:
- 12g NiC-12 (1 mol of NiC-12/70.7g NiC-12) = 0.17 mol of NiC-12
- The grams cancel, leaving us with moles of NiC-12, so the answer is 0.17 moles of NiC-12 in a 12 g sample.
<em>P.S. C-12 or C12 just means that the Carbon atom has an atomic mass of 12amu and a molar mass of 12g/mol, or just regular carbon.</em>
Answer:
NaCl will only conduct electricity in solutions
Explanation:
For electrical conduction, free mobile electrons as seen in most metals must be present or ions which are charged particles must be available for solutions and molten substances.
- Sodium chloride is an ionic compound without free mobile electrons or ions despite being ionic.
- It will maintain a subtle and unique charge stability when in solid form.
- In solid, the ions are not free to move and remain locked up in the solid mass.
- When introduced into a solution, the ions becomes free to move and this will aid electrical conduction.
Answer:
72.53% is the yield of CrCl3
Explanation:
Given
Reaction:
Cr2O3(s) + 3 CCl4(l) → 2 CrCl3(s) + 3 COCl2(aq)
CCl4 is in excess and 17.6g Cr2O3 present
The reaction yields 26.6g of CrCl3
To Find:
% yields of the reaction
Also given
Molar mass of CrCl3 = 158.35g/mol
Molar mass of Cr2O3 = 152.00 g/mol
By the stoichiometry of the reaction
1 mole of Cr2O3 gives 2 moles of CrCl3
0r
1 x1 52 g of Cr2O3 gives 2x 158.35 g of CrCl3
= 1 52 g of Cr2O3 gives 316.70 g of CrCl3
17.6 g of Cr2O3 gives (17.6÷152) × 316.70 g CrCl3
= 36.67 g CrCl3
but actual yield is only 26.6g
so % yield is (26.6 ÷÷ 36.67) × 100
= 72.53% is the yield of CrCl3
