<span>Answer:
For this problem, you would need to know the specific heat of water, that is, the amount of energy required to raise the temperature of 1 g of water by 1 degree C. The formula is q = c X m X delta T, where q is the specific heat of water, m is the mass and delta T is the change in temperature. If we look up the specific heat of water, we find it is 4.184 J/(g X degree C). The temperature of the water went up 20 degrees.
4.184 x 713 x 20.0 = 59700 J to 3 significant digits, or 59.7 kJ.
Now, that is the energy to form B2O3 from 1 gram of boron. If we want kJ/mole, we need to do a little more work.
To find the number of moles of Boron contained in 1 gram, we need to know the gram atomic mass of Boron, which is 10.811. Dividing 1 gram of boron by 10.811 gives us .0925 moles of boron. Since it takes 2 moles of boron to make 1 mole B2O3, we would divide the number of moles of boron by two to get the number of moles of B2O3.
.0925/2 = .0462 moles...so you would divide the energy in KJ by the number of moles to get KJ/mole. 59.7/.0462 = 1290 KJ/mole.</span>
Answer:
the third one
Explanation:
if you look at it mathematically its the one that makes the most sense
1 mol --------- 6.02x10²³ atoms
6.3 moles ---- ??
atoms = 6.3 * 6.02x10²³
= 3.7926x10²⁴ atoms
hope this helps!
Answer:
Australia is correct
Explanation:
Because it is not attached to any other place
C = 84.71%
H = 5.88%
O = 9.41%
<h3>Further explanation</h3>
Given
3-phenylphenol, C12H10O
Required
The mass percent
Solution
Ar C = 12 g/mol
Ar H = 1 g/mol
Ar O = 16 g/mol
MW C12H10O = 170 g/mol
The mass percent :
C = (12x12/170) x 100%
C = 84.71%
H = (10x1)/170) x 100%
H = 5.88%
O = (1 x 16)/170 x 100%
O = 9.41%
