Advertisements
Advertisements
Question
Solve the following problem:
Find out the molar mass of the following compounds:
Sodium carbonate, decahydrate (Na2CO3.10H2O)
(At. mass: Cu = 63.5; S = 32; O = 16; H = 1; Na = 23; C = 12; Fe = 56; N = 14)
Solution
Molar mass of Na2CO3.10H2O
= (2 × At. mass Na) + (1 × At. mass C) + (13 × At. mass O) + (20 × At. mass H)
= (2 × 23) + (1 × 12) + (13 × 16) + (20 × 1)
= 46 + 12 + 208 + 20
= 286 g mol–1
Molar mass of Na2CO3.10H2O = 286 g mol–1
APPEARS IN
RELATED QUESTIONS
Calculate the amount of carbon dioxide that could be produced when 2 moles of carbon are burnt in 16 g of dioxygen.
A sample of drinking water was found to be severely contaminated with chloroform, CHCl3, supposed to be carcinogenic in nature. The level of contamination was 15 ppm (by mass).
- Express this in percent by mass.
- Determine the molality of chloroform in the water sample.
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.
Explain the term mole fraction
Why does the molarity of a solution depend upon temperature?
Solve the following problem:
Find out the molar mass of the following compounds:
Copper sulphate crystal (CuSO4.5H2O)
(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:
3.75 × 10−1
Solve the following problem:
Perform the following calculation. Round off your answer to two digits.
`1/(3.40xx10^24)`
Perform each of the following calculations. Round off your answers to three digits.
(3.26104) (1.54106)
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.
Give your reason for rejecting each of the others.
Solve the following problem:
What weight of calcium oxide will be formed on heating 19.3 g of calcium carbonate?
(At. wt.: Ca = 40; C = 12; O = 16)
When light is passed through water containing a few drops of milk, it shows a bluish tinge. This is due to the ______ of light by milk and the phenomenon is called ______. This indicates that milk is a ______ solution.
Non-metals are usually poor conductors of heat and electricity. They are non-lustrous, non-sonorous, non-malleable and are coloured.
Name a lustrous non-metal.
A child wanted to separate the mixture of dyes constituting a sample of ink. He marked a line by the ink on the filter paper and placed the filter paper in a glass containing water as shown in Fig.2.3. The filter paper was removed when the water moved near the top of the filter paper.
(i) What would you expect to see, if the ink contains three different coloured components?
(ii) Name the technique used by the child.
(iii) Suggest one more application of this technique.
Calculate the mass of sodium sulphate required to prepare its 20% (mass percent) solution in 100g of water?
If 500 mL of a 5 M solution is diluted to 1500 mL, what will be the molarity of the solution obtained?
If the concentration of glucose \[\ce{(C6H12O6)}\] in blood is 0.9 g L–1, what will be the molarity of glucose in blood?
Sulphuric acid reacts with sodium hydroxide as follows:
\[\ce{H2SO4 + 2NaOH -> Na2SO4 + 2H2O}\]
When 1 L of 0.1 M sulphuric acid solution is allowed to react with 1 L of 0.1 M sodium hydroxide solution, the amount of sodium sulphate formed and its molarity in the solution obtained is:
(i) 0.1 mol L–1
(ii) 7.10 g
(iii) 0.025 mol L–1
(iv) 3.55 g
What is the difference between molality and molarity?
If 4 g of \[\ce{NaOH}\] dissolves in 36 g of \[\ce{H2O}\], calculate the mole fraction of each component in the solution. Also, determine the molarity of solution (specific gravity of solution is 1g mL–1).
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 |
Molarity of liquid HCl will be if the density of the solution is 1.17 g/cc.
The molarity of urea (molar mass 60 g mol−1) solution by dissolving 15 g of urea in 500 cm3 of water is ______.
Find the molality of solution if boiling point increases by 1.75 K and molal elevation constant of solvent is 5K kg mol-1.
