Answer:
- m = 1,000/58.5
- b = - 1,000 / 58.5
1) Variables
- molarity: M
- density of the solution: d
- moles of NaCl: n₁
- mass of NaCl: m₁
- molar mass of NaCl: MM₁
- total volume in liters: Vt
- Volume of water in mililiters: V₂
- mass of water: m₂
2) Density of the solution: mass in grams / volume in mililiters
3) Mass of NaCl: m₁
Number of moles = mass in grams / molar mass
⇒ mass in grams = number of moles × molar mass
m₁ = n₁ × MM₁
4) Number of moles of NaCl: n₁
Molarity = number of moles / Volume of solution in liters
M = n₁ / Vt
⇒ n₁ = M × Vt
5) Substitue in the equation of m₁:
m₁ = M × Vt × MM₁
6) Substitute in the equation of density:
d = [M × Vt × MM₁ + m₂] / (1000Vt)
7) Simplify and solve for M
- d = M × Vt × MM₁ / (1000Vt) + m₂/ (1000Vt)
- d = M × MM₁ / (1000) + m₂/ (1000Vt)
Making the simplistic assumption that the dissolved NaCl(s) does not affect the volume of the solvent water means 1000Vt = V₂
- d = M × MM₁ / (1000) + m₂/ V₂
m₂/ V₂ is the density of water: 1.00 g/mL
- d = M × MM₁ / (1000) + 1.00 g/mL
- M × MM₁ / (1000) = d - 1.00 g/mL
- M = [1,000/MM₁] d - 1,000/ MM₁
8) Substituting MM₁ = 58.5 g/mol
- M = [1,000/58.5] d - [1,000/ 58.5]
Comparing with the equation Molarity = m×density + b, you obtain:
- m = 1,000/58.5
- b = - 1,000/58.5
it decreases the density of the object the air bubbles take up space. it increases the volume of the object slightly but the objects weight remains the same, hence the objects density decreases
Answer:
Energy is transferred between the earths surface and atmosphere.Energy move place to place
Answer;
(3) Substance A is an element and substance Z is a compound.
Explanation;
-A compound is a substance formed when two or more chemical elements are chemically bonded together, such as water, carbon dioxide, methane, etc while an element is a pure chemical substance made of same type of atoms, such includes, oxygen, potassium, hydrogen, carbon, etc.
- Compounds can be broken
down or decomposed into simpler substances: elements cannot be broken down chemically into simpler substances .
Answer:
0.0187 M
Explanation:
Step 1: Write the balanced neutralization reaction
NaOH + HCl ⇒ NaCl + H₂O
Step 2: Calculate the reacting moles of HCl
18.7 mL of 0.01500 M HCl react.
0.0187 L × 0.01500 mol/L = 2.81 × 10⁻⁴ mol
Step 3: Calculate the reacting moles of NaOH
The molar ratio of HCl to NaOH is 1:1. The reacting moles of NaOH are 1/1 × 2.81 × 10⁻⁴ mol = 2.81 × 10⁻⁴ mol.
Step 4: Calculate the molarity of NaOH
2.81 × 10⁻⁴ moles are in 15.00 mL of NaOH.
[NaOH] = 2.81 × 10⁻⁴ mol/0.01500 L = 0.0187 M
