Answer: Single replacement Reaction
Explanation:
A replacement reaction is a chemical reaction in which an element replaces another element in a compound especially when it is more reactive than the former. There are two types of replacement reaction, the single and double replacement reaction.
In the former, one element which is usually more reactive than the other replaces it . For example in the single replacement, a more reactive metal replaces a less reactive metal and also a more reactive non metal can replace a less reactive non metal.
A + BC → B + AC
looking at the equation aove, you can see that B replaces A
Also In double replacement, the elements in the both reacting compounds are replaced or exchanged to form new compounds as can be illustrated in the equation
AB + CD —— AC + BD
In the case of Coach Kwan, she follows the Single replacement model as she substitutes a less active and tired player with an active one.
Answer:
Copper sulphate is an acidic salt: It is the product of the reaction between a weak copper base and a strong acid , H2SO4
Litmus has a red colour in acidic solutions:
Conclusion: Acidic copper sulphate solution turns blue litmus to red
Baking soda is a basic salt : It is the reaction product of a weak acid , CO2 and a strong base , NaOH
Litmus has a blue colour in basic solutions:
Conclusion: basic baking soda solution turns red litmus to blue
