#6 should be the independent variable because that's the one you can control
<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:
95.3g
Explanation:
Given parameters:
Mass of water = 540g
Percentage by mass of solution = 15%
Unknown:
Mass of sucrose = ?
Solution;
To solve this problem, we must understand that a solution is made up of solute dissolved in a solvent. A solute is the solid dissolved in another. The solvent is the is dissolving medium;
Percentage by mass of solute in solution =
Mass of solution = mass of water + Mass of sucrose = 540 + M
where M is the mass of sucrose;
therefore;
= 15
Solving for M gives 95.3g
Mass of sucrose is 95.3g
Answer:
It's not atom it is an element Strontium.