Answer: 
Explanation: A double displacement reaction is one in which exchange of ions take place.
According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side. Thus chemical equations are balanced.
Answer:
B. CaCl₂ + H₂CO₃ → CaCO₃ + 2HC
Explanation:
A balanced reaction has the same number of atoms in the both sides of the reaction. In the options:
A. CaCl₂ + H₂CO₃ → 2CaCO₃ + HCI
In this reaction there is 1 Ca in reactants and 2 in products -<em>The reaction is unbalanced-</em>
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<h3>B. CaCl₂ + H₂CO₃ → CaCO₃ + 2HCl
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There is 1 Ca is both sides, 2Cl, 2H, 1C and 3 Oxygens -<em>The reaction is balanced</em>
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C. CaCl₂ + 2H₂CO₃ → CaCO₃ + HCI
There is 1 Ca in both sides but 2Cl in reactants and 1 in Cl -<em>The reaction is unbalanced-</em>
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D. 2CaCl₂ + H₂CO₃ →CaCO₃ + HCI
There are 2 Ca in reactants and 1 in Ca -<em>The reaction is unbalanced-</em>
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
The domain that is an onion is the <span>Eukaryote.
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Below are the choices:
<span>The independent variable is the number of dry cells, and the dependent variable is the length of time the bulb works.
</span><span>The independent variable is the length of time the bulb works, and the dependent variable is the number of dry cells.
</span><span>The independent variable is the number of dry cells, and the dependent variable is the amount of energy available.
</span><span>The independent variable is the amount of energy available, and the dependent variable is the number of dry cells.
</span>
I think the answer is <span>The independent variable is the number of dry cells, and the dependent variable is the amount of energy available.</span>
