A famous naval battle that was crucial in ending the Persian threat to the Greeks took place at

A 0.3146 g sample of a mixture of NaCl ( s ) and KBr ( s ) was dissolved in water. The resulting solution required 45.70 mL of 0

Masteriza [31]

Answer:

The answer to the question is

The mass percentage of NaCl(s) in the mixture is 49.7%

Explanation:

The given variables are

mass of sample of mixture = 0.3146 g

Volume of AgNO₃ required to react comletely with the chloride ions = 45.70 mL

Concentration of the AgNO₃ added = 0.08765 M

The equations for the reactions oare

NaCl(aq) + AgNO₃ (aq) = AgCl(s) + NaNO₃(aq)

AgNO₃ (aq) + KBr (aq) → AgBr (s) + KNO₃

The equation for the reaction shows one mole of NaCl reacts with one mole of AgNO₃ to form one mole of AgCl

Thus 45.70 mL of 0.08765 M solution of AgNO₃ contains $\frac{45.7}{1000} (0.08765) = 0.004 moles$

Therefore the sum of the number of moles of Br⁻ and Cl⁻

precipitated out of the solution = 0.004 moles

Thus if the mass of NaCl in the sample = z then the mass of KBr = y

However the mass of the sample is given as 0.3146 g which means the molarity of the solution is 0.004 moles

given by

$\frac{z}{58.44} + \frac{y}{119} = 0.004 moles$ and z + y = 0.3146

Therefore z = 0.3146 - y which gives

$\frac{(0.3146-y)}{58.44} + \frac{y}{119} = 0.004 moles$

-8.7×10⁻³y +0.54×10⁻³ = 0.004

or 8.7×10⁻³y = 1.37769× 10⁻³

y = 0.158 g and z = 0.156 Thus the mass of NaCl = 0.156 g and the mass percentage = 0.156/0.3146×100 = 49.7% NaCl

The mass percentage of NaCl(s) in the mixture is 49.7%

8 0

3 years ago

What method of heat transfer takes place when particles of matter move from one place to another in a liquid

Alecsey [184]

Answer:

CONVECTION

Explanation:

CONVECTION: In liquids and gases, convection is usually the most efficient way to transfer heat. Convection occurs when warmer areas of a liquid or gas rise to cooler areas in the liquid or gas.

5 0

3 years ago

Read 2 more answers

Explain how elements are arranged on the periodic table. What does the table tell you when you read it like sentences in a book

DochEvi [55]

Explanation:

In periodic table:

Elements are arranged according to their atomic number in increasing order.
When we move left to right we move along a period.The period in the periodic table tell us about the principal quantum number,(n).
When move from top to bottom we are moving in group. The group in the periodic table tell us about the number of the valence electrons present in the valence shell of the elements of the particular group.