<u>Answer:</u> The molarity of NaCl solution is 0.0489 M
<u>Explanation:</u>
Molarity is defined as the amount of solute expressed in the number of moles present per liter of solution. The units of molarity are mol/L. The formula used to calculate molarity:
.....(1)
We are given:
Given mass of NaCl = 0.8 g
Molar mass of NaCl = 58.44 g/mol
Volume of the solution = 280 mL
Putting values in equation 1, we get:
Hence, the molarity of NaCl solution is 0.0489 M
The correct option is C. A calorimeter is an isolated system. In isolated systems there is no exchange whatsoever with the surrounding. In an isolated system, an endothermic reaction results in a decrease in the temperature of the system. This is in contrast to the effect of an endothermic reaction in an open system. The heat of reaction remains a positive quantity.
The law that states that the properties of the elements are periodic functions of their atomic numbers.
D, because isotopes all have the same atomic number but different number of neutrons