Advertisements
Advertisements
Question
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.
Advertisements
Solution
The metre stick is graduated in millimetres i.e. 1 mm to 1000 mm, and 1 mm = 0.1 cm. Therefore, if length is measured in centimetres, the least count of metre stick is 0.1 cm. The results 12.6 cm has the least count of 0.1 cm and is acceptable result.
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.
Calculate the amount of carbon dioxide that could be produced when 1 mole of carbon is burnt in 16 g of dioxygen.
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?
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.
Explain the term molality
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:
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)
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:
5.16 × 104
Solve the following problem:
Write the following number in ordinary decimal form:
0.00477 × 105
Solve the following problem:
Write the following number in ordinary decimal form:
5.00858585
Solve the following problem:
Perform the following calculation. Round off your answer to two digits.
`(1.4xx10^9)/((2.77xx10^3)(3.76xx10^5))`
Perform the following calculation. Round off your answer to three digits.
(8.39 107) (4.53 109)
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:
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?
What are the favourable qualities given to gold when it is alloyed with copper or silver for the purpose of making ornaments?
What will be the molality of the solution containing 18.25 g of \[\ce{HCl}\] gas in 500 g of water?
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?
The molarity of pure water is ______.
With increase of temperature, which of these changes?
The molarity of urea (molar mass 60 g mol−1) solution by dissolving 15 g of urea in 500 cm3 of water is ______.
