D) Volume
All other answers involve chemical reactions and are hence, not physical properties.
For which of the following activities might you want to hire a chemist?
Answer: D. testing a rock sample for gold content
Which of the following procedures involves a physical change in one of the substances?
Answer: C. separating a salt solution by evaporating the water
Answer:
NaOH is limiting
Explanation:
Hcl + NaOH ------------ Nacl + H2O
Given 7.81g 5.24g
mol weights 1+35.5 23+16+1
36.5 40
No of Moles 7.81/36.5 5.24/40
0.2139 0.131
No of moles = weight/ molecular weight
No of moles of NaOH is lower so it is limiting as according to equation one mole of Hcl requires mole of NaOH so equal number of moles are required. NaOH is 0.131 which is far lower than 0.2139
-------- represents arrow in forward direction in equation
Explanation:
mass = moles * molar mass
molar mass of carbon dioxide (CO2) = 12+32 = 44
= 19.5* 44 = 858
proof
moles = mass /molar mass
= 858/44 = 19.5 moles
