Give two important uses of washing
[question] Question. Give two important uses of washing soda and baking soda. [/question] [solution] solution: Two important uses of washing soda and baking soda are as follows- (1) Washing soda- (a) It is used in glass, soap, and paper industries. (b) It is used to remove permanent hardness of water. (2) Baking soda- (a) It is used as baking powder. Baking powder is a mixture of baking soda and a mild acid known as tartaric acid. When it is heated or mixed in water, it releases $\mathrm{CO}_{2}...
Plaster of Paris should be stored in a moisture-proof container.
[question] Question. Plaster of Paris should be stored in a moisture-proof container. Explain why? [/question] [solution] solution: Plaster of Paris should be stored in a moisture-proof container because Plaster of Paris, a powdery mass, absorbs water (moisture) to form a hard solid known as gypsum. [/solution]...
A milkman adds a very small amount of
[question] Question. A milkman adds a very small amount of baking soda to fresh milk. (a) Why does he shift the $\mathrm{pH}$ of the fresh milk from 6 to slightly alkaline? (b)Why does this milk take a long time to set as curd? [/question] [solution] solution: (a) The milkman shifts the $\mathrm{pH}$ of the fresh milk from 6 to slightly alkaline because in alkaline condition, milk does not set as curd easily. (b) Since this milk is slightly basic than usual milk, acids produced to set the curd a...
Fresh milk has a $\mathrm{pH}$ of 6 . How do you think the
[question] Question. Fresh milk has a $\mathrm{pH}$ of 6 . How do you think the $\mathrm{pH}$ will change as it turns into curd ? Explain your answer. [/question] [solution] solution: The $\mathrm{pH}$ of milk is $6 .$ As it changes to curd, the $\mathrm{pH}$ will reduce because curd is acidic in nature. The acids present in it decrease the $\mathrm{pH}$. [/solution]...
Five solutions $\mathrm{A}, \mathrm{B}, \mathrm{C}, \mathrm{D}$ and $\mathrm{E}$ when tested
[question] Question. Five solutions A, B, C, D and E when tested with universal indicator showed pH as 4, 1, 11, 7 and 9 , respectively. Which solution is (a) neutral ? (b) strongly alkaline ? (c) strongly acidic ? (d) weakly acidic ? (e) weakly alkaline ? Arrange the pH in increasing order of hydrogen-ion concentration [/question] [solution] solution: (a) Neutral - Solution D with $\mathrm{pH} 7$ (b) Strongly alkaline - Solution C with pH 11 (c) Strongly acidic - Solution B with $\mathrm{pH} 1$...
Why do acids not show acidic behaviour
[question] Question. Why do acids not show acidic behaviour in the absence of water ? [/question] [solution] solution: Acids do not show acidic behaviour in the absence of water because there are no hydrogen ions available for conduction of electricity. Acids dissociate in the presence of water to give free hydrogen ions. It is the hydrogen ions that are responsible for the acidic behaviour. [/solution]...
Why does distilled water not conduct electricity,
[question] Question. Why does distilled water not conduct electricity, whereas rain water does? [/question] [solution] solution: Distilled water is a pure form of water and is devoid of any ionic species. Therefore, it does not conduct electricity. Rain water, being an impure form of water, contains many ionic species such as acids and therefore it conducts electricity. [/solution]...
Compounds such as alcohols and glucose also contain hydrogen but are not categorized as acids.
[question] Question. Compounds such as alcohols and glucose also contain hydrogen but are not categorized as acids. Describe an activity to prove it. [solution] solution: Acitivity Step 1- Two nails are fitted on a cork and are kept it in a 100 mL beaker. Step 2- The nails are then connected to the two terminals of a 6-volt battery through a bulb and a switch. Step 3- Some dilute HCl is poured in the beaker and the current is switched on. Step 4- The same experiment is then performed with glucos...
Write word equations and then balanced equations
[question] Question. Write word equations and then balanced equations for the reaction taking place when - (1) Dilute sulphuric acid reacts with zinc granules. (2) Dilute hydrochloric acid reacts with magnesium ribbon. (3) Dilute sulphuric acid reacts with aluminium powder. (4) Dilute hydrochloric acid reacts with iron filings. [/question] [solution] solution: [/solution]...