Answer: <span>A fewer number of particles of the sample will dissolve in 1 minute.
That is because normally the solubility and rate of solubility of the salts in water increase with the temperature. This is, the higher the temperature the higher and faster the number of particles that the water can dissolve. So, at 70°C more particles will be dissolved in water in 1 minute than at 20°C.
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There are 4 significant figures! Start counting after the first non-zero digit :)
Hope this helps.
Answer: B or C
Explanation: The question does not include the variable or steps Brian is using so either one could be correct. It has to be the one that he is controlling though. This is because a control group is used to rule out any alternate explanations. Therefore the answer should be the one that he is trying to test out.
Ka is the acid dissociation equilibrium constant. The larger the value of the Ka, the stronger is the acid. To find Ka from pKa, the equation is:
pKa = -log[Ka]
@pKa = 7
7 = -log[Ka]
Ka = 1×10⁻⁷
@pKa = 10
10 = -log[Ka]
Ka = 1×10⁻¹⁰
This, pKa 7 is more acidic than pKa 10. The scale factor would be:
1×10⁻⁷/1×10⁻¹⁰ = 1,000
<em>Therefore, Compound A is 1,000 times more acidic than Compound B.</em>
