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3 years ago

I AM GIVING BRAINLIEST PLEASEE HELPPPP I NEED HELPPPPPP PLEAEEEEEE

Chemistry

2 answers:

Helga [31]3 years ago

4 0

Answer:

Interestingly enough, I'm not getting

0.0341% w/v

either. Here's why.

Start by calculating the percent composition of chlorine,

, in calcium chloride, This will help you calculate the mass of chloride anions,

−

, present in your sample.

To do that, use the molar mass of calcium chloride, the molar mass of elemental chlorine, and the fact that

mole of calcium chloride contains

moles of chlorine atoms.

35.453

g mol

−

110.98

g mol

−

⋅

100

63.89% Cl

This means that for every

100 g

of calcium chloride, you get

63.89 g

of chlorine.

As you know, the mass of an ion is approximately equal to the mass of the neutral atom, so you can say that for every

100 g

of calcium chloride, you get

63.89 g

of chloride anions,

−

This implies that your sample contains

0.543

g CaCl

⋅

63.89 g Cl

−

100

g CaCl

0.3469 g Cl

−

Now, in order to find the mass by volume percent concentration of chloride anions in the resulting solution, you must determine the mass of chloride anions present in

100 mL

of this solution.

Since you know that

500 mL

of solution contain

0.3469 g

of chloride anions, you can say that

100 mL

of solution will contain

100

mL solution

⋅

0.3469 g Cl

−

500

mL solution

0.06938 g Cl

−

Therefore, you can say that the mass by volume percent concentration of chloride anions will be

% m/v = 0.069% Cl

−

−−−−−−−−−−−−−−−−−−−

I'll leave the answer rounded to two sig figs, but keep in mind that you have one significant figure for the volume of the solution.

Explanation:

True [87]3 years ago

3 0

Answer:

0.479 M or mol/L

Explanation:

So Molarity is moles/litres of solution...often written as M=mol/L

So here we are given grams of BaCl2 which we have to convert to moles. To convert to moles of BaCl2 we have to divide 63.2 g BaCl2 by molar mass of BaCl2 which is 208.23 g/mol so you get 63.2/208.23 = 0.3035 moles of BaCl2

Second step is converting the 634mL to litres by simply dividing by 1000 because we know 1 litre has 1000ml so 634/1000 = 0.634L

Now we just plug these guys in our molarity formula M=mol/L

M= 0.3035/0.634 = 0.479 M or mol/L

You might be interested in

Write an equation that expresses the law of thermodynamics in terms of heat and work

Anettt [7]

We write DE = q+w, where DE is the internal energy change and q and w are heat and work, respectively.

(b)Under what conditions will the quantities q and w be negative numbers?

q is negative when heat flows from the system to the surroundings, and w is negative when the system does work on the surroundings.

As an aside: In applying the first law, do we need to measure the internal energy of a system? Explain.

The absolute internal energy of a system cannot be measured, at least in any practical sense. The internal energy encompasses the kinetic energy of all moving particles in the system, including subatomic particles, as well as the electrostatic potential energies between all these particles. We can measure the change in internal energy (DE) as the result of a chemical or physical change, but we cannot determine the absolute internal energy of either the initial or the final state. The first law allows us to calculate the change in internal energy during a transformation by calculating the heat and work exchanged between the system and its surroundings.

3 0

3 years ago

32 g of sulfur will react with 48 g of oxygen to produce 80 g of sulfur trioxide. If 32 g of sulfur and 100 g of oxygen are plac

Lina20 [59]

Answer:

Since the container is consealed, and O2 will no be completely consumed, the total mass of material in the container will be 80 grams SO3+ 52 grams O2 = 132 grams (option B)

Explanation:

Step 1: Data given

Mass of sulfur = 32.00 grams

Mass of oxygen = 48.00 grams

Molar mass of sulfur = 32.07 g/mol

Molar mass of oxygen = 32 g/mol

Molar mass of SO3 = 80.07 g/mol

Step 2: The balanced equation

2S + 3O2 → 2SO3

Step 3: Calculate moles S

Moles S = Mass S / molar mass S

Moles S = 32.0 grams / 32.07 g/mol

Moles S = 0.998 moles

Step 4: Calculate moles O2

Moles O2 = 100.0 grams / 32.0 g/mol

Moles O2 = 3.125 moles

Step 5: Calculate the limiting reactant

For 2 moles S we need 3 moles O2 to produce 2 moles SO3

S is the limiting reactant. It will completely be consumed (0.998 moles)

O2 is in excess, there will be consumed 3/2 * 0.998 = 1.497 moles

There will remain 3.125- 1.497 = 1.628 moles O2

This is 1.628 moles * 32 g/mol = 52.1 grams

Step 6: Calculate moles SO3

For 2 moles S we need 3 moles O2 to produce 2 moles SO3

For 0.998 moles S there will react 0.998 moles SO3

Step 6: Calculate mass SO3

Mass SO3 = moles SO3 * molar mass SO3

Mass SO3 = 0.998 moles * 80.07 g/mol

Mass SO3 = 79.9 grams ≈ 80 grams

There will be produced 80 grams of SO3

Since the container is consealed, and O2 will no be completely consumed, the total mass of material in the container will be 80 grams SO3+ 52 grams O2 = 132 grams (option B)

4 0

3 years ago

Giving brainliest for answers too ALL 3

Tasya [4]

2 and 2 and 3 hope that helped

5 0

3 years ago

Read 2 more answers

Suppose a student repeats a measurement two times and then calculates the standard deviation. Because the standard deviation is

Valentin [98]

Answer:

The correct answer is option B, that is, a small standard deviation suggests greater precision.

Explanation:

A determination of precision is a standard deviation, it is more reliable in comparison to mean deviation. The square root of the total of the squares of the deviations divided by the degree of freedom for the array of measurements is known as standard deviation.

The precision of low standard deviation value is more as the results or observations demonstrated by the low standard deviation are more close to average.

7 0

3 years ago

If you had a 100 mL of a solution of 0.01 M NaF, how many moles would that solution contain?

Daniel [21]

Answer:

0.001 mole of NaF.

Explanation:

From the question given above, the following data were obtained:

Volume of solution = 100 mL

Molarity = 0.01 M

Mole of NaF =?

Next, we shall convert 100 mL to litre (L). This can be obtained as follow:

1000 mL = 1 L

Therefore,

100 mL = 100 mL × 1 L / 1000 ml

100 mL = 0.1 L

Thus, 100 mL is equivalent to 0.1 L.

Finally, we shall determine the number of mole of NaF present in the solution. This can be obtained as follow:

Volume of solution = 0.1 L

Molarity = 0.01 M

Mole of NaF =?

Molarity =mole /Volume

0.01 = mole of NaF / 0.1

Cross multiply

Mole of NaF = 0.01 × 0.1

Mole of NaF = 0.001 mole.

Thus, 0.001 mole of NaF is present in 100 mL of the solution.

5 0

3 years ago