<u>Given information:</u>
Mass of NaCl (m) = 87.75 g
Volume of solution (V) = 500 ml = 0.5 L
Molar mass of NaCl (M) = 58.44 g/mol
<u>To determine:</u>
The molarity of NaCl solution
<u>Explanation:</u>
Molarity is defined as the number of moles of solute(n) dissolved per liter of solution (V)
i.e. M = moles of solute/liters of solution = n/V
Moles of solute (n) = mass of solute (m)/molar mass (M)
moles of NaCl = 87.75 g/58.55 g.mol-1 = 1.499 moles
Therefore,
Molarity of NaCl = 1.499 moles/0.5 L = 2.998 moles/lit ≅ 3 M
<u>Ans: (D)</u>
Answer:
Explanation:
A heating curve graphically represents the phase transitions that a substance undergoes as heat is added to it. ... The first change of phase is melting, during which the temperature stays the same while water melts. The second change of phase is boiling, as the temperature stays the same during the transition to gas.
The molarity of the stock solution of luminol is 1.2 M
<u><em>calculation</em></u>
step 1: find the moles of luminol using (moles= mass/molar mass) formula
molar mass of Luminol= 177 g/mol
moles is therefore= 16.0 g/ 177 g/mol=0.0904 moles
Step 2: find the molarity using (molarity= moles/volume in liters) formula
convert Ml into liters = 75.0/1000= 0.075 L
molarity is therefore= 0.0904 moles/ 0.075 L= 1.2M
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
I think it might be about 65.31 N on the moon...I've never done this before but what I did was divide 400N by 9.8 to get their mass then multiply the MASS by 1.6 to get the WEIGHT on the moon
