Answer : The molality of NaCl is, 1.95 mol/kg
Explanation :
Formula used for Elevation in boiling point :

where,
= change in boiling point = 
= boiling point constant for water = 
m = molality
i = Van't Hoff factor = 2 (for electrolyte)
The dissociation
will be,

So, Van't Hoff factor = Number of solute particles =
= 1 + 1 = 2
Now put all the given values in the above formula, we get:


Therefore, the molality of NaCl is, 1.95 mol/kg
Valence electrons largely determine the chemical properties of an element.
Answer:
b) Baking soda
Explanation:
Baking soda is sodium hydrogen carbonate, NaHCO₃.
It reacts with water according to the equation
NaHCO₃ + H₂O ⇌ H₂CO₃ + NaOH
Thus, baking soda is a base because it increases the concentration of hydroxide ions in water.
<em>Water</em> is <em>neutral</em>.
<em>Lemon juice</em> is an <em>acid</em> because it contains citric acid.
An <em>insulator </em>is a substance that does not conduct electricity. Insulators are <em>neither acidic nor basic</em>.
The ans should be C. ( if i'm not wrong )
This is because the solubility of oxygen increases when temperature in the water is cooler. Cold water can hold more dissolved oxygen than warm water, thus having a higher concentration of oxygen.