Answer:
9.79740949850 moles
Explanation:
- 1 mole = Avogardo's Number <<6.022 E 23 <<particles, atoms, etc.>>
- This problem can be solved using dimensional analysis by multiplying atoms (5.9E24 atoms) by (1) mole and then dividing the number by Avogardo's number (6.022 E 23 atoms).
- Note: E = * 10
Side Note: Please let me know if you need any clarifications about this!
<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:
6.61 Pounds
Solution:
Step 1: Calculate Mass of Water as;
Density = Mass ÷ Volume
Solving for Mass,
Mass = Density × Volume ------ (1)
As,
Density of Water = 1 g.cm⁻³
And,
3 L of Water = 3000 cm³
Putting values in equation 1,
Mass = 1 g.cm⁻³ × 3000 cm³
Mass = 3000 g
Step 2: Convert Grams into Pounds;
As,
1 Gram = 0.002204 Pounds
So,
3000 Grams = X Pounds
Solving for X,
X = (3000 Grams × 0.002204 Pounds) ÷ 1 Gram
X = 6.61 Pounds
