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>
It depends, for example, it is quite important to know the Kelvin scale (i.e 0 degrees Celsius is 273 K and -273 degrees Celsius is 0 K ) when dealing gases. But I don't know other situations where you would need to know other temperature scales.
Hope this helps and also if you are using Fahrenheit 1 Fahrenheit is -17.22 degrees Celsius
Answer:
0.006342moles
Explanation:
1000ml of NaOH contain 0.151moles
42ml of NaOH contain (42*0.151)/1000 moles
=0.006342moles
Answer:
Explanation
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One
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Ca(OH)2 + 2HNO3 -----> Ca(NO3)2 + H2O
Focus on the NO3. This is an odd problem and you usually do not focus on the complex ion. But this one works easiest if you do.
The problem now is going to be the oxygens. There are 2 with the Calcium and only 1 free one going to the water. (The NO3 has been taken care of in the last step).
Ca(OH)2 + 2HNO3 -----> Ca(NO3)2 + 2H2O
Count the atoms. I think this equation is balanced.
atom Left Right Result
Ca 1 1 Balanced
O 8 8 Balanced
H 2 + 2 2*2 Balanced
N 2 2 Balanced
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Two
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CH4 + O2====> CO2 + H2O
Start with the hydrogens.
The right side requires a 2
CH4 + O2 ===> CO2 + 2H2O
Now look at the oxygens. There are 4 on the right. and only 2 on the left. You need to multiply O2 by 2
CH4 + 2O2 ===> CO2 + 2H2O
Each side has 1 Carbon 4 hydrogens and 4 oxygens. The equation is balanced.
