We know, Given mass = Molar mass * Number of moles.
A.) <span>1.25 mol CaF</span>₂
Number of moles = 1.25
Molar mass = 78
So, Mass = 78 * 1.25 = 97.5 g
B.) 3.4 mol (NH₄)₂SO₄
Number of moles = 3.4
Molar mass = 132
Mass = 3.4 * 132 = 448.8 g
Hope this helps!
Answer is: boiling point will be changed by 4°C.
Chemical dissociation of aluminium nitrate in water: Al(NO₃)₃ → Al³⁺(aq) + 3NO⁻(aq).
Change in boiling point: ΔT =i · Kb · b.
Kb - molal boiling point elevation constant of water is 0.512°C/m, this the same for both solution.
b - molality, moles of solute per kilogram of solvent., this is also same for both solution, because ther is same amount of substance.
i - Van't Hoff factor.
Van't Hoff factor for sugar solution is 1, because sugar do not dissociate on ions.
Van't Hoff factor for aluminium nitrate solution is approximately 4, because it dissociates on four ions (one aluminium cation and three nitrate anions). So ΔT is four times bigger.
Answer:
pH = 4.09
Explanation:
molarity of oxalic acid in the solution
= 0.1 x 25 / (25 + 35)
= 0.0417 M
molarity of NaOH in the solution
= 0.1 x 35 / (25 +35)
= 0.0583 M
H2C2O4 + NaOH -------------------> NaHC2O4 + H2O
0.0417 0.0583 0 0
0 0.0166 0.0417
now second acid -base titration
NaHC2O4 + NaOH -------------------> Na2C2O4 + H2O
0.0417 0.0166 0 0
0.0251 0 0.0166 ---
now
pH = pKa2 + log [Na2C2O4 / NaHC2O4]
pH = 4.27 + log (0.0166 / 0.0251)
pH = 4.09
From the relative atomic mass of each element, it is possible to determine each element's molar mass by multiplying the molar mass constant (1 g/mol) by the atomic weight of that particular element. The molar mass value can be used as a conversion factor to facilitate mass-to-mole and mole-to-mass conversions.
The question is incomplete, the complete question is;
An alcohol thermometer makes use of alcohol's changing _______ in order to measure temperature. As the temperature goes up, the alcohol contained in the thermometer increases in volume, filling more of the thermometer's tube.
A.
mass
B.
state
C.
chemical composition
D.
density
Answer:
D.
density
Explanation:
Every kind of thermometer makes use of a change in a particular physical property of a substance as a measure of temperature. It must be a property that changes with temperature.
Density of a substance changes with temperature. Even though the mass of alcohol in glass remains constant, but its volume increases or decreases with change in temperature leading to a change in volume and consequently a change in density of the alcohol in glass. This change is used as a measure of the change in temperature.
