First consider and take note of the following:
1. When 2 or more finite amounts of substances are mix together (with different temperature) the final temperature is never equivalent to the initial temperature of any of the substances involved.
2. The substances meet at an equilibrium temperature.
3. Heat transfers from a higher temperature to a lower temperature.
Only choice (3) satisfies the conditions.
1.267 x 10 ^ 24 is the total number of atoms
Answer:
The answer to your question is: The first option is correct.
Explanation:
From the data given, we conclude that as the amount of salt increases, the boiling point of water increases.
Options
If salt is added to water, the water will boil at a higher temperature This is the hypothesis for the experiment.
Salt makes water boil. This statement is not true.
If water is boiling, it must have salt added to it. This statement is incorrect, it is not the goal of the experiment.
If salt is added to water, the water will get cloudy There is not evidence of that from the information given.
Answer:
The mass of 10 cm³of a 0.4 g/dm³ solution of sodium carbonate is 0.004 grams
Explanation:
The question is with regards to density calculations
The density of the given sodium carbonate solution, ρ = 0.4 g/dm³
The volume of the given solution of sodium carbonate, V = 10 cm³ = 0.01 dm³


Therefore, we have;

The mass, "m", of the sodium carbonate in = ρ×V = 0.4 g/dm³ × 0.01 dm³ = 0.004 g
The mass of 10 cm³ (10 cm³ = 0.01 dm³) of a 0.4 g/dm³ solution of sodium carbonate, m = 0.004 g.
In order to balance this, you have to count
each element where the elements in the reactants side and the product side
should have equal number of molecules. The balanced reaction is as follows:
KOH + H3PO4 = KH2PO4 +H2O