The lab report contains the theory, process, data and calculation of the experiment. The theory and process are remains fixed for a particular experiment. Thus there is no chance to get error from these two part. The calculation depends upon the reading or data of the experiment. The calculation is also unique and based on the data. Thus the error come from the data of the experiment. As for example for a titration experiment the data recorded in the process from the burret is the source of error, on which the calculation depends.
Answer: 12 ( answer not among the option)
Explanation:
From the equation of reaction; P4O10+ H2O -----> H3PO4, it is unbalanced.
One can only get the exact number of ''Hydrogen atom'' if it is well balanced.
Adding '4' to H3PO4 on the RHS and '6' to H2O on LHS of the equation would give a balanced equation such as;
P4O10 + 6H2O -----> 4 H3PO4
Therefore the number of hydrogen atoms found on the reactant is 12.
Given the mass of Titanium = 3.8 lb
Density of Titanium is 4.506 
We can calculate the volume of Titanium using density and mass.
Converting mass from lb to g:
Calculating the volume of Titanium using density and mass:
Converting volume from 
:
I think it’s C since the ice changes from solid to a liquid which is physical and then it reacts with calcium metal making the calcium hydroxide which is chemical change. And another sign of it being chemical was the release of gas.
