Advertisements
Advertisements
Question
What will be the molality of the solution containing 18.25 g of \[\ce{HCl}\] gas in 500 g of water?
Options
0.1 m
1 M
0.5 m
1 m
Advertisements
Solution
1 m
Explanation:
The number of moles is given by the following formula,
Moles = `"Mass"/"Molar mass"` ......(1)
The number of moles of \[\ce{HCl}\] is calculated by using equation (1) as follows,
Moles of HCl = `(18.25 g)/((36.5 g)/(mol)` = 0.5 mol
The morality (m) is given by the formula:
m = `"n"/"mass of solvent"_((kg))`
On substituting the values in the above equation:
Molality = `(0.5 mol xx 1000 kg)/500` = 1 m
APPEARS IN
RELATED QUESTIONS
To make a saturated solution, 36 g of sodium chloride is dissolved in 100 g of water at 293 K. Find its concentration at this temperature.
Calculate the amount of carbon dioxide that could be produced when 1 mole of carbon is burnt in air.
What is the concentration of sugar (C12H22O11) in mol L–1 if its 20 g are dissolved in enough water to make a final volume up to 2 L?
Solve the following problem:
Find out the molar mass of the following compounds:
Mohr’s salt [FeSO4(NH4)2SO4.6H2O]
(At. mass: Cu = 63.5; S = 32; O = 16; H = 1; Na = 23; C = 12; Fe = 56; N = 14)
Solve the following problem:
Write the following number in ordinary decimal form:
3.49 × 10−11
Solve the following problem:
Write the following number in ordinary decimal form:
43.71 × 10−4
Solve the following problem:
Perform the following calculation. Round off your answer to two digits.
`33/(9.00xx10^-4)`
Solve the following problem:
Perform the following calculation. Round off your answer to two digits.
`((4xx10^-3)(9.9xx10^-7))/((789)(1.002xx10^-10)(0.3xx10^2))`
A 1.000 mL sample of acetone, a common solvent used as a paint remover, was placed in a small bottle whose mass was known to be 38.0015 g.
The following values were obtained when the acetone-filled bottle was weighed: 38.7798 g, 38.7795 g and 38.7801 g. How would you characterise the precision and accuracy of these measurements if the actual mass of the acetone was 0.7791 g?
Solve the following problem:
Your laboratory partner was given the task of measuring the length of a box (approx 5 in) as accurately as possible, using a metre stick graduated in milimeters. He supplied you with the following measurements:
12.65 cm, 12.6 cm, 12.65 cm, 12.655 cm, 126.55 mm, 12 cm.
State which of the measurements you would accept, giving the reason.
Solve the following problem:
The hourly energy requirements of an astronaut can be satisfied by the energy released when 34 grams of sucrose are “burnt” in his body. How many grams of oxygen would be needed to be carried in space capsule to meet his requirement for one day?
If the concentration of glucose \[\ce{(C6H12O6)}\] in blood is 0.9 g L–1, what will be the molarity of glucose in blood?
Which of the following terms are unitless?
(i) Molality
(ii) Molarity
(iii) Mole fraction
(iv) Mass percent
What is the difference between molality and molarity?
Match the following physical quantities with units
| Physical quantity | Unit |
| (i) Molarity | (a) g mL–1 |
| (ii) Mole fraction | (b) mol |
| (iii) Mole | (c) Pascal |
| (iv) Molality | (d) Unitless |
| (v) Pressure | (e) mol L–1 |
| (vi) Luminous intensity | (f) Candela |
| (vii) Density | (g) mol kg–1 |
| (viii) Mass | (h) Nm–1 |
| (i) kg |
What quantity (in mL) of a 45% acid solution of a monoprotic strong acid must be mixed with a 20% solution of the same acid to produce 800 mL of a 29.875% acid solution?
Molarity of liquid HCl will be if the density of the solution is 1.17 g/cc.
