In the case of the liquid meniscus, a concave meniscus that is what one usually observes takes place when the molecules of the liquid are fascinated towards the container. This takes place with water and a glass tube. A convex meniscus takes place when the molecules exhibit a stronger attraction with each other in comparison to the container, as in the case of glass and mercury.
The shape of the liquid meniscus is determined by the relative magnitudes of the cohesive forces in the liquid and adhesive forces between the liquid and its container.
Answer:
A. Strong initial heating caused some of the hydrate sample to spatter out of the crucible.
Explanation:
Hi
The percentage of water in the sample is lower than expected.
A. Strong initial heating caused some of the hydrate sample to spatter out of the crucible:
If part of the sample is splashed from the crucible the mass of water detected will be less.
B. The dehydrated sample absorbed moisture after heating:
If the sample absorbs water after heating the percentage of water would be higher than expected.
C. The amount of the hydrate sample used was too small:
Depending on the sample size, different procedures can be chosen for analysis.
D. The crucible was not heated to constant mass before use:
In many occasions the crucible is heated next to the sample and not in previous form.
E. Excess heating caused the dehydration sample to decompose:
If the sample decomposes during heating, the analysis should be discarded.
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Answer: 37.5grams of Cu(NO3)2
Cu(1mol) + 2HNO3(2mol) —> Cu(NO3)2 + H2
<em>125 grams of Cu(1mol) reacts with 75 grams of HNO3(2mol)</em>
<em><u>HNO3 is the limiting substance, therefore, 75 grams is the limiting quantity.</u></em>
<em>Therefore, 2mol of HNO3 forms 1mol of Cu(NO3)2</em>
<em>75 grams of HNO3 forms...75grams x 1mol/2mol = 37.5 grams of Cu(NO3)2</em>
