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3 years ago

What is the molality of a solution made by dissolving 5.2 g of NaCl in 100 g of water?

Chemistry

1 answer:

stich3 [128]3 years ago

8 0

Answer:

The molality is 0,89

Explanation:

A molal solution indicates the moles of solute in 1 kg of solvent (1000 g). First, we calculate the weight of 1 mol of NaCl:

Weight NaCl= Weight Na + Weight Cl=23g + 35,5 g=58,5 g/mol

58,5 g----1 mol NaCl

5,2 g----x=(5,2 gx1 mol NaCl)/58,5 g=0,089 mol NaCl

100g water-----0,089 mol NaCl

1000g water----x=(1000g waterx0,089 mol NaCl)/100 g water

x=0,89 mol NaCl----> 0,89 m

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In metallic bonds, electrons are referred to as electrons.

GrogVix [38]

Answer:

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3 years ago

What is the percent by mass of water in Na S04.10H20?

dalvyx [7]

Answer:

Percent by mass of water is 56%

Explanation:

First of all calculate the mass of hydrated compound as,

Mass of Sodium = Na × 2 = 22.99 × 1 = 45.98 g

Mass of Sulfur = S × 1 = 32.06 × 1 = 32.06 g

Mass of Oxygen = O × 14 = 16 × 14 = 224 g

Mass of Hydrogen = H × 20 = 1.01 × 20 = 20.2 g

Mass of Na₂S0₄.10H₂O = 322.24 g

Secondly, calculate mass of water present in hydrated compound. For this one should look for the coefficient present before H₂O in molecular formula of hydrated compound. In this case the coefficient is 10, so the mass of water is...

Mass of water = 10 × 18.02

Mass of water = 180.2 g

Now, we will apply following formula to find percent of water in hydrated compound,

%H₂O = Mass of H₂O / Mass of Hydrated Compound × 100

Putting values,

%H₂O = 180.2 g / 322.24 g × 100

%H₂O = 55.92 % ≈ 56%

3 0

3 years ago

Match each part of the electrochemical cell with its function.

umka21 [38]

Hi!

The correct options would be:

1. Cathode - reduction

The cathode is the negatively charged electrode, and so has an excess of electrons. Cations (positively charged ions) are attracted to the cathode, and gain electrons to acquire a neutral charge. The process in which a gain of electron occurs is called reduction.

2. Anode - oxidation

The opposite occurs at the anode which is positively charged and attracts negatively charged ions, anions. These anions lose their electrons at the anode to acquire a neutral charge, and the process involving loss of electrons is known as oxidation.

3. Salt Bridge - ion transport

Salt bridge is a physical connection between the the anodic and cathodic half cells in an electrochemical cell and is a pathway that facilitates the flow of ions back and forth these half cells. Salt bridge is involved in maintaining a neutral condition in the electrochemical cells, and its absence would result in the accumulation of positive charge in the anodic cell, and negative charge in the cathodic cell.

4. Wire - electron transport

Wires have a universal role of being a pathway for the transport of electrons in circuit. This role is also the same in the wires involved in an electrochemical cells where they are used to transport electrons from the anodic half cell, and this electron transport results in the generation of electricity in the internal circuit of the electrochemical cell.

Hope this helps!

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3 years ago

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Nookie1986 [14]

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2 years ago

Calculate the equilibrium constant for the reaction using the balanced chemical equation and the concentrations of the substance

Oliga [24]

Answer:

4.75 is the equilibrium constant for the reaction.

Explanation:

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