Advertisements
Advertisements
Question
Give reason for the following:
When concentrated sulphuric acid is added to sugar/glucose, a black mass is left behind.
Advertisements
Solution
The carbohydrates contain carbon, hydrogen and oxygen. The hydrogen and oxygen are always in ratio of 2:1 which is absorbed by acid in the form of water, thus leaving carbon behind. This is also called as charring.
APPEARS IN
RELATED QUESTIONS
What would you observe in the following case?
Hot concentrated sulphuric acid is added to sodium chloride crystals.
Give reason for the following:
When solution of sulphur dioxide is exposed to air, it gets converted to sulphuric acid.
Give reason for the following:
When concentrated sulphuric acid is exposed to air, its volume increases and it becomes slightly dilute.
Give reason for the following:
Concentrated sulphuric acid should not be added to oxalic acid or formic acid in the open laboratory.
Choose the current answer from the options given below :
The catalyst used for the oxidation of SO2 to SO3 in contact process is
A, B, C and D summarize the properties of sulphuric acid depending on whether it is dilute or concentrated. Choose the property (A, B, C or D), depending on which is relevant to each of the preparations (i) to (ii).
A. Dilute acid (typical acid properties)
B. Non-volatile acid
C. Oxidizing agent
D. Dehydrating agent
(i) Preparation of hydrogen chloride.
(ii) Preparation of ethane from ethanol
(iii) Preparation of copper sulphate from copper oxide.
What property of sulphuric acid is shown by the reaction of concentrated sulphuric acid when heated with :
(i) Potassium nitrate
(ii) carbon
Give one equation to show the following property of sulphuric acid:
As a non-volatile acid
Give balanced chemical equation to prepare the following salt:
Lead sulphate from lead carbonate
Name the anion present in the following compound:
Compound D, when warmed with dilute sulphuric acid, gives a gas that turns acidified dichromate solution green.
