Answer:
D
Explanation:
The correct thing to do in this case would be to <u>repeat the experiment.</u>
The scientist would need to repeat the experiment in order to double-check the accuracy. If the accuracy is indeed doubtful, he/she can be able to trace the source of the error by repeating the experiment.
The correct option is D.
Answer:
c. Can't decide with information given.
Explanation:
The chemical and physical processes can be classified as endothermic or exothermic. The first one happens when the system absorbs heat, so the temperature of the surroundings will decrease, and the other one happens when the system releases heat, then the temperature of the surrounds will increase.
Precipitation is the formation of a solid in a solution. The process can happen with absorption or release of heat, it depends on the substance. So, with the information given it's impossible to say it.
Moles are a unit of measure used to convert between different quantities like grams, molarity or volume.
Dimensional analysis is doing math with units. They multiply, divide and cancel out just like numbers. This is why like for area of a rectangle: 2m × 3m = 6m² is in units of distance squared and volume is in units of distance cubed.
Example Chemistry question.
Now, say you have 10 grams of NaCl salt that is added to 1 L water and you want to know the concentration. You would look at the periodic table and find the atomic mass of both Sodium (Na = 23 g/mol) and Chloride (Cl = 35.5 g/mol).
Once you have the atomic mass of both elements add them together to get the atomic mass of the compound NaCl = 23 g/mol + 35.5 g/mol = 58.5 g/mol
set up the multiplication so that grams cancels out during multiplication. Like so ....

Grams cancel leaving moles NaCl. The concentration of the solution, molarity = moles/liter
Divide 0.17 moles NaCl by 1 Liters = 0.17 Molarity NaCl
Hope this helps, let me know if you have any questions.