Answer:

Explanation:

Data:
Mass of NaCl = 4.6 g
Mass of water = 250 g
Calculations:
Mass of solution = mass of NaCl + mass of water = 4.6 g + 250 g = 254.6 g.

Answer:

Explanation:
We are asked to find the volume of a substance.
We are given the density and the mass. The density of a substance is its mass per unit volume. The formula for calculating density is:

We know the density of the substance is 13.6 grams per cubic centimeter and the mass is 3.0 grams.
Substitute these values into the formula.

We are solving for the volume, so we must isolate the variable v. First, cross multiply. Multiply the first numerator by the second denominator, then multiply the first denominator by the second numerator.


Multiply on the right side of the equation.

The variable is being multiplied by 13.6 grams per cubic centimeters. The inverse operation of multiplication is division, so we divide both sides of the equation by 13.6 g/cm².


The units of grams cancel.


The original measurement of density has 3 significant figures and the measurement of mass has 2. Our answer must have the least number of sig figs, which is 2. For the number we found, that is the hundredth place. The 0 in the thousandth place tells us to leave the 2 in the hundredth place.

The volume of the substance is approximately <u>0.22 cubic centimeters.</u>
Answer:
A tin atom and 2 molecules containing two hydrogen atoms bonded to one oxygen atom.
Explanation:
Equation of reaction:
SnO2 + 2H2 ---> Sn + 2H2O
According to Dalton's postulates:
1. All elements are made up of small indivisible particles called atoms
2. The atom cannot be created nor destroyed
3. The atoms of the same element are alike in every aspect and differ from atoms of all other elements
4. During a chemical reaction there is a combination of atoms in small whole numbers.
From the given options, the one that satisfies the postulates of Dalton is:
"A tin atom and 2 molecules containing two hydrogen atoms bonded to one oxygen atom"
This is because it gives a balanced chemical equation for the number of atoms reacting for each element is equal to the number of atoms of each element produced. This is in accordance with the postulate that atoms are neither created nor destroyed.
The three other postulates are also obeyed. The small whole number ratio for the reactants and products in the chemical reaction is 1 : 2 : 2.