Answer is: volume of KBr is 357 mL.
c(KBr) = 0,716 M = 0,716 mol/L.
m(KBr) = 30,5 g.
n(KBr) = m(KBr) ÷ M(KBr).
n(KBr) = 30,5 g ÷ 119 g/mol.
n(KBr) = 0,256 mol.
V(KBr) = n(KBr) ÷ c(KBr).
V(KBr) = 0,256 mol ÷ 0,716 mol/L.
V(KBr) = 0,357 L · 1000 mL/L = 357 mL.
Answer : The correct option is, They are different units of concentration.
Explanation :
Molarity : It is defined as the number of moles of solute present in one liter of solution.
Formula of molarity :
Mass percent : It is defined as the mass of solute present in the mass of solution.
Formula of mass percent :
Hence, both are the different unit of concentration.
Answer:
2
Explanation:
Mass of water molecule = mass of hydrated salt - mass of anhydrous salt
Mass of water molecule = 5.00 - 4.26 = 0.74g of water molecule.
Number of moles = mass / molarmass
Molar mass of water = 18.015g/mol
No. of moles of water = 0.74 / 18.015 = 0.0411 moles.
Mass of BaCl2 present =?
1 mole of BaCl2 = 208.23 g
X mole of BaCl2 = 4.26 g
X = (4.26 * 1) / 208.23
X = 0.020
0.020 moles is present in 4.26g of BaCl2
Mole ratio between water and BaCl2 =
0.0411 / 0.020 = 2
Therefore 2 molecules of water is present the hydrated salt.
You have a few steps to solve this one. First, we'll find the molar mass by percentage of each element in the molecule. Then, we'll divide each of those relative masses by the atomic mass of each element. The number of times the mass divides into the relative mass is the number of atoms of that element in the molecule:
C: 284.5 x .76 = 216.22
H: 284.5 x .128= 36.416
O: 284.5 x .112 = 31.864.
Now we divide out each element's atomic mass (from the periodic table). it's okay if they're approximated from the decimal answer.
C: 216.22 ÷ 12.011 ≈ 18
H: 36.416 ÷ 1.008 ≈36
O: 31.864 ÷ 15.999 ≈ 2
Therefore, the molecular formula is C18H36O2.
The empirical formula would be found by dividing out all factors of those subscript numbers. In our case, all of them can be divided by 2. The empirical formula would be C9H18O
Answer:
Explanation:
specific heat of granite s = .79 J / g / k
let the mass of granite = m
heat lost by granite = heat gained by water
heat lost = mass x specific heat x drop in temperature
= m x .79 x (80 - 20.45)
heat gained by water
= 3000 x 4.186 x (20.45- 20)
heat lost by granite = heat gained by water
m x .79 x 59.55 = 3000 x 4.186 x .45
m = 120.12 g .
