I'm not sure about 2 but in 3 it would float
Reaction of option c produces precipitate.
Rhodium on reacting with potassium phosphate produces rhodium phosphate which remain in solution due to low lattice energy for rhodium phosphate.
Niobium on reacting with lithium carbonate produces niobium carbonate and it will remain in aqueous form.
Cobalt on reacting with zinc nitrate produces cobalt nitrate. This, Co(NO3 )2 is insoluble precipitate and settles at bottom whereas zinc ion will remain in solution as follows:

Potassium ion on reacting with sodium sulfide produces potassium sulfide which remain in solution
Pseudo-science is not considered real science because it is not testable.
Answer: Option A
<u>Explanation:</u>
Pseudoscience primarily includes beliefs, theories or practices that are somehow incompatible with the scientific facts. The pseudoscience can’t be tested on the basis of science.
Let’s take an example of astrology. Some people believe that stars and other celestial bodies draw a significant impact on their life i.e. Good or bad thing it's just because their stars are working either in a positive or negative manner.
But, this belief doesn’t have any well-proved or authentic background over which the whole concept can rely on. Hence, pseudoscience is not taken as a real science as a lack of strong proves.
Answer:175⋅mL of the given sulfuric acid
Explanation: