Answer:
The percent by mass of 3.55 g NaCl dissolved in 88 g water is 3.88%
Explanation:
When a solute dissolves in a solvent, the mass of the resulting solution is a sum of the mass of the solute and the solvent.
A percentage is a way of expressing a quantity as a fraction of 100. In this case, the percentage by mass of a solution is the number of grams of solute per 100 grams of solution and can be represented mathematically as:

In this way it allows to precisely establish the concentration of solutions and express them in terms of percentages.
In this case:
- mass of solute: 3.55 g
- mass of solution: 3.55 g + 88 g= 91.55 g
Replacing:

Percent by mass= 3.88%
<u><em>The percent by mass of 3.55 g NaCl dissolved in 88 g water is 3.88%</em></u>
Answer: -
12.41 g
Explanation: -
Mass of CO₂ = 42 g
Molar mass of CO₂ = 12 x 1 + 16 x 2 = 44 g / mol
Number of moles of CO₂ = 
= 0.9545 mol
The balanced chemical equation for this process is
2C₆H₆ + 15O₂ → 12CO₂ + 6H₂O
From the balanced chemical equation we see
12 mol of CO₂ is produced from 2 mol of C₆H₆
0.9545 mol of CO₂ is produced from 
= 0.159 mol of C₆H₆
Molar mass of C₆H₆ = 12 x 6 + 1 x 6 =78 g /mol
Mass of C₆H₆ =Molar mass x Number of moles
= 78 g / mol x 0.159 mol
= 12.41 g
Answer: The bond between boron and hydrogen in boron trihydride is covalent bond.
Explanation:
The type of bonding between the atoms forming a compound is determined by using the electronegativity difference between the atoms. According to the pauling's electronegativity rule:
- If
, then the bond is non-polar. - If
, then the bond will be covalent. - If
, then the bond will be ionic.
We are given:
Electronegativity for boron = 2.0
Electronegativity for hydrogen = 2.1

As,
is less than 1.7 and not equal to 0. Hence, the bond between boron and hydrogen is covalent bond.
100% find the gfm of both sides then divide
Answer:
The correct answer is - 4.
Explanation:
As we known and also given that the total of the superscripts that is mass numbers, A in the reactants and products must be the same.The mass of products A can understand and calculated by this -
The sum of the product mass number of products = mass of reactant
237Np93 →233 Pa91 +AZX is the equation,
Solution:
Mass of reactants = 237
Mass of products are - Pa =233 and A = ?
233 + A = 237
A = 237 - 233
A = 4
So the equation will be:
237Np93 →233 Pa91 +4He2 (atomic number Z = 2 ∵ difference in the atomic number of reactant and products)