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3 years ago

6) What is the molality of 0.4 moles of KCl in 1500 g of solvent?

Chemistry

1 answer:

qaws [65]3 years ago

3 0

Answer:

Molality = 0.267 mol/Kg

Explanation:

Given data:

Moles of KCl = 0.4 mol

Mass of solvent = 1500 g

Molality of solution = ?

Solution:

Formula:

Molality = moles of solute / kg of solvent

Now we will convert the g into kg.

1500 g× 1kg/ 1000 g

1.5 kg

Now we will put the values in formula.

Molality = 0.4 mol/ 1.5 kg

Molality = 0.267 mol/Kg

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koban [17]

Answer:

They are heavy metals.

Explanation:

Heavy metals are generally defined as metals with relatively high densities, atomic weights, or atomic numbers.

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3 years ago

A gas system has an initial number of moles of 0.693 moles with the volume unknown. When the number of moles changes to 0.928 mo

lara [203]

Answer:

The initial volume in mL is 5959.2 mL

Explanation:

As the number of moles of a gas increases, the volume also increases. Hence, number of moles and volumes are directly proportional i.e

n ∝ V

Where n is the number of moles and V is the volume

Then, n = cV

c is the proportionality constant

∴n/V = c

Hence n₁/V₁ = n₂/V₂

Where n₁ is the initial number of moles

V₁ is the initial volume

n₂ is the final number of moles

and V₂ is the final volume.

From the question,

n₁ = 0.693 moles

V₁ = ?

n₂ = 0.928 moles

V₂ = 7.98 L

Putting the values into the equation

n₁/V₁ = n₂/V₂

0.693 / V₁ = 0.928 / 7.98

Cross multiply

∴ 0.928V₁ = 0.693 × 7.98

0.928V₁ = 5.53014

V₁ = 5.53014/0.928

V₁ = 5.9592 L

To convert to mL, multiply by 1000

∴ V₁ = 5.9592 × 1000 mL

V₁ = 5959.2 mL

Hence, the initial volume in mL is 5959.2 mL

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2 years ago

Iron Choose one: A. is alloyed with carbon and chromium to make stainless steel. B. was the first of the common metals (iron, al

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Answer:

A. is alloyed with carbon and chromium to make stainless steel.

Explanation:

Steel is an alloy formed mainly of iron and carbon but some other metals like chromium are also added in little amounts.

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Although the cost of steel is low, it has a very high tensile strength and that's why it is used in tools, ships, buildings, trains and in various types of infrastructures.

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2 years ago

What reaction might we use to synthesize nickel sulfate,niso4? Write equations for acid base neutralization. Include states in y

il63 [147K]

Answer:

Here's what I get

Explanation:

1. Nickel sulfate

base + acid ⟶ salt + water

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Hydroxides of transition metals are insoluble; most sulfates are soluble.

$\underbrace{\hbox{Ni(OH)$_{2}$(s)}}_{\hbox{base}} + \underbrace{\hbox{H$_{2}$SO$_{4}$(aq)}}_{\hbox{acid}} \longrightarrow \, \underbrace{\hbox{NiSO$_{4}$(aq)}}_{\hbox{salt}} + \underbrace{\hbox{2H$_{2}$O(l)}}_{\hbox{water}}$

2. Carbonate + acid

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3 years ago

A sample of carbon dioxide occupies a 5.13 dm3 container at STP. What is the volume of the gas at a pressure of 286.5 kPa and a

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Considering the ideal gas law and STP conditions, the volume of the gas at a pressure of 286.5 kPa and a temperature of 12.9°C is 1.8987 L.

<h3>Definition of STP condition</h3>

The STP conditions refer to the standard temperature and pressure. Pressure values at 1 atmosphere and temperature at 0 ° C are used and are reference values for gases. And in these conditions 1 mole of any gas occupies an approximate volume of 22.4 liters.

<h3>Ideal gas law</h3>

Ideal gases are a simplification of real gases that is done to study them more easily. It is considered to be formed by point particles, do not interact with each other and move randomly. It is also considered that the molecules of an ideal gas, in themselves, do not occupy any volume.

The pressure, P, the temperature, T, and the volume, V, of an ideal gas, are related by a simple formula called the ideal gas law:

P×V = n×R×T

where:

P is the gas pressure.
V is the volume that occupies.
T is its temperature.
R is the ideal gas constant. The universal constant of ideal gases R has the same value for all gaseous substances.
n is the number of moles of the gas.

<h3>Volume of gas</h3>

In first place, you can apply the following rule of three: if by definition of STP conditions 22.4 L are occupied by 1 mole of carbon dioxide, 5.13 L (5.13 dm³= 5.13 L, being 1 dm³= 1 L) are occupied by how many moles of carbon dioxide?

$amount of moles of carbon dioxide=\frac{5.13 Lx1 mole of carbon dioxide}{22.4 L}$