I believe the answer you are looking for is the 4th one.
Answer:
B. 0.2.
Explanation:
<em>n = mass/molar mass</em>
mass of CaCO₃ = 20 g, molar mass of CaCO₃ = 100.0869 g/mol.
<em>∴ n = mass/molar mass = </em>(20 g)/(100.0869 g/mol) <em>= 0.1998 ≅ 0.2 mol.</em>
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<em>So, the right choice is: B. 0.2.</em>
Change in velocity over time is acceleration.
You're finding acceleration .
<u>Answer:</u> The solubility of B is high than the solubility of A.
<u>Explanation:</u>
The solubility is defined as the amount of substance dissolved in a given amount of solvent. More the solute gets dissolved, high will be the solubility and less the solute dissolved, low will be the solubility.
For the given observations:
Mass of undissolved substance of substance A is more than Substance B at every temperature. This implies that less amount of solute gets dissolved in the given amount of solvent.
Hence, substance B has high solubility than substance A.