Class 10th Some important questions of science
Class 10th Sami important questions of science Q. Why does dry HCL gas not change the colour of the dry litmus paper? Ans. The colour of litmus paper changes only in the presence of ions like hydrogen (H + ) or hydronium (H 3 O + ) 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. Q. Here are some results of solutions tested with universal indicator paper Sulphuric acid: Red Metal polish: Dark blue Washing-up liquid: Yellow Milk of magnesia: Light blue Oven cleaner: Purple Car battery acid: Pink Arrange the solutions in order of their increasing pH values (starting with the one with the lowest pH). Ans. Sulphuric acid < car battery acid < washing up liquid < milk of magnesia < metal polish < oven cleaner since: Red : pH = 1 Pink : pH = 3-4 Yellow: pH = 5-6 Light blue...