Why does dry hcl gas not change the colour of the dry litmus paper

Students can refer to the following Acids Bases and Salts MCQ Questions for Class 10 with Answers provided below based on the latest curriculum and examination pattern issued by CBSE and NCERT. Our teachers have provided here a collection of multiple choice questions for Acids Bases and Salts Class10covering all topics in your textbook so that students can assess themselves on all important topics and thoroughly prepare for their exams Acids Bases and Salts MCQ Questions for Class 10 Chemistry with Answers We have provided below Acids Bases and Salts MCQ Questions for Class 10 with answers which will help the students to go through the entire syllabus and practice multiple choice questions provided here with solutions. As Acids, Bases and Salts Acids Bases and Salts MCQ Questions for Class 10 Question. Why does dry HCl gas not change the colour of the dry litmus paper? a. Blue litmus becomes dry in presence of dry HCl gas b. No H 3O+ ions will be present, litmus changes colour only in the presence of H 3O+ ions c. HCl gas acts asa dehydrating agent d. None of the above 4 Question. When dilute hydrochloric acid is added to granulated zinc placed in a test tube, the observation made is that (1) the surface of the metal turns shining (2) the reaction mixture turns milky (3) odour of chlorine is observed (4) a colourless and odourless gas is evolved with bubbles 18. The reaction of metal with acid results in the formation of 4 Question. Acetic acid was added to a solid X kept ...

INTEXT QUESTIONS Q1. You have been provided with three test tubes. One of them contains distilled water and the other two contain an acidic solution and a basic solution, respectively. If you are given only red litmus paper, how will you identify the contents of each test tube? Ans. If the colour of red litmus paper gets changed to blue, then it is a base and if there is no colour change, then it is either acidic or neutral. Thus, basic solution can be easily identified. Let us mark the three test tubes as A, B, and C. A drop of the solution in A is put on the red litmus paper. Same is repeated with solution Band C. If either of them changes colour to blue, then it is basic. Therefore, out of three, one is eliminated. Out of the remaining two, any one can be acidic or neutral. Now a drop of basic solution is mixed with a drop of each of the remaining two solutions separately and then the nature of the drops of the mixtures is checked. If the colour of red litmus turns blue, then the second solution is neutral and if there is no change in colour, then the second solution is acidic. This is because acidic and basic solutions neutralize each other. Hence, we can distinguish between the three types of solutions. INTEXT QUESTIONS Q1. Why should curd and sour substances not be kept in brass and copper vessels? Ans. Curd and other sour substances contain acids. Therefore, when they are kept in brass and copper vessels, the metal reacts with the acid to liberate hydrogen gas and h...

Lemon juice, carbonated soft drink and curd contain acids. Therefore, they turn litmus paper into red. ​ ​Moistened NH 3 is a base while soap solution contains base. Therefore, they turn litmus blue.​ Dry HCl has no effect on litmus as it does not furnish H + ions in aqueous solutions. Therefore, it does not change its colour.​ subject Red litmus Blue litmus Dry H C I gas Red Blue Moistened N H 3 gas Blue Blue Lemon juice Red Red Carbonated soft drink Red Red Curd Red Red Soap solution Blue Blue

Question . Why does dry HCl gas not change the colour of the dry litmus paper? Answer: The colour of litmus paper changes only in the presence of ions like hydrogen (H +) or hydronium (H 3O +) ions. HCl can produce these ions only in the form of aqueous solution. Hence dry HCl gas does not change the colour of dry litmus paper

Colour of the litmus paper is changed by the hydrogen ions. Dry HCl gas does not contain `H^(+)` ions. It is only in the aqueous solution that an acid dissociates to give ions. Since in this case, neither HCl is in the aqueous form nor the litmus paper is wet, therefore, the colour of the litmus paper does not change.

Hint :Acids are those which give hydrogen ion $ () $ . However, dry litmus paper doesn’t work at all in case of gaseous substances.