It is endothermic reaction ΔH>0 (sign is +).
Because it is spontaneous reaction ΔG<span><0 (Gibbs free energy)
</span>ΔG=ΔH-TΔS, so must be TΔS>ΔH and ΔS<span>>0 (sign +).</span>
Answer:
It will lead to overestimation of the percent recovery
Explanation:
The percent recovery refers to the percentage of the pure compound recovered after a chemical process. It is a ratio of the pure compound recovered to the original substance multiplied by 100%.
If the sample was incompletely dried and the recrystallization solvent is still present, the percent recovery will be overestimated and we will have a value that is greater than the accurate percent recovery due to solvent impurities present.
Answer:
give options!!!!!!!!!!!!!!
<h3>
Answer:</h3>
45°C
<h3>
Explanation:</h3>
We are given;
- Quantity of heat = 1.95 kJ
- Mass of lead = 500 g
- Initial temperature = 15° C
- heat capacity of lead is 130 J/kg°C
We are required to calculate the final temperature;
- We need to know that the quantity of heat is given by the formula;
Q = mass,m × specific heat,c × Change in temperature,ΔT
ΔT = final temperature - initial temperature
We can rearrange the formula to calculate the change in temperature
ΔT = Q ÷ (m×c)
Therefore;
ΔT = 1950 J ÷ (0.5 kg × 130 J/Kg°C)
= 30°C
But,
Final temperature = ΔT + Initial temperature
= 15°C + 30°C
= 45°C
Therefore, the final temperature is 45°C
I think a good strategy for these kind of problems is to just choose the atom with the highest mass number. At any rate, the answer actually is (and I guessed it as) (2) Francium-220. It has a half life of about 30 seconds.