Answer:
First write the balanced equation for the reaction of HCl with Zn (NOTE: the previous answer did NOT do this and thus obtained an incorrect answer)
Zn + 2HCl ==> ZnCl2 + H2(g)
moles of H2 desired: PV = nRT
n = PV/RT = (1 atm)(10L)/(0.0821 Latm/Kmol)(298K)
n = 0.409 mole H2 desired
moles Zn needed:
0.409 moles H2 x 1 mole Zn/2 moles HCl = 0.204 moles Zn needed
mass Zn needed = 0.204 moles Zn x 65.4 g/mol = 13.4 g Zn needed (to 3 sig. figs.)
Explanation:people always get this wrong but i got you
The answer is (b.) alkyne series.
Answer: D. The energy required to boil a substance
Explanation: I just took the quiz and got it correct :)
I think science is based on nature and it's surroundings <span />
Answer:
b. 2 mol of KI in 500. g of water
Explanation:
We have to apply the colligative property of freezing point depression.
The formula is: ΔT = Kf . m . i
As the (Kf . m . i) is higher, then the freezing temperature will be lower.
i refers to the Van't Hoff factor (number of ions dissolved in the solution)
KI → K⁺ + I⁻ (i =2)
Kf is constant so, we have to search for the highest m (molality)
Molality means the moles of solute in 1kg of solvent.
The highest m is option b → 2 mol of KI / 0.5 kg = 4 mol/kg
a. 1 mol of KI / 0.5 kg = 2 mol/kg
c. 1 mol of KI / 1kg = 1 mol/kg
d. 2 mol of KI / 1kg = 2 mol/kg
1000 g = 1kg. In order to determine molality we need to convert the mass (g) of solvent to kg
