Answer:

Explanation:
According to the Law of Conservation of Mass, the mass of the products must equal the mass of the reactants.
- mass products = mass reactants
In this problem, the reaction is:

- The reactants are iron and oxygen. We know the mass of the iron sample is 10 grams.
- The product is ferric oxide. The mass of the ferric oxide sample is 18.2 grams.

We want to find how many grams of oxygen reacted. We have to get the oxygen by itself. 10 is being added to oxygen. The inverse of addition is subtraction. Subtract 10 from both sides of the equation.



<u>8.2 grams of oxygen </u>reacted with 10 grams of iron to form 18.2 grams of ferric oxide.
Answer:
B. Molarity will decrease
Explanation:
Molarity is one of the measures of the molar concentration of a solution. It is calculated by dividing the number of moles of the solute by the volume of the solvent. This means that the higher the amount of solute in relation to the volume of solvent, the higher the molarity of that solution.
In essence, adding water to a solution dilutes it i.e it increases the solvent's volume in relation to the solute, causing the molarity to decrease. In a nutshell, diluting a solution (by adding water or more solvent) causes the molarity of such solution to decrease. For example, if water is added to a 0.70 molar solution of CuSO4, the molarity of the solution will DECREASE.
Bond Angle in the molecule of Methane according to the VSEPR theory is that it has a bond angle of 109.5 degrees with respect to the Carbon and the Hydrogen
Answer:
0.119 moles
Explanation:
Given that,
Mass measured by Nurse Antonio is 7 grams of NaCl
To find,
The no of moles of NaCl
Solution,
The number of moles is given by

m is given mass
M is molar mass
For NaCl, molar mass is 23+35.5 = 58.5 grams
So,

Therefore, there are 0.119 moles of NaCl.