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2 years ago

1. What is an indicator and how does it work?

Chemistry

1 answer:

Goryan [66]2 years ago

7 0

Answer:

Chemical indicator, any substance that gives a visible sign, usually by a color change, of the presence or absence of a threshold concentration of a chemical species, such as an acid or an alkali in a solution. An example is the substance called methyl yellow, which imparts a yellow color to an alkaline solution.

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Convert 8.7 mg to ibs

rjkz [21]

Answer:

Explanation:

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Calculate the volume in milliliters of a 0.420mol / L barlum chlorate solution that contains 25.0 g of barium chlorate (Ba(ClO 3

Pachacha [2.7K]

Answer: The volume of barium chlorate is 195.65 mL

Explanation:

To calculate the volume of solution, we use the equation used to calculate the molarity of solution:

$\text{Molarity of the solution}=\frac{\text{Mass of solute}\times 1000}{\text{Molar mass of solute}\times \text{Volume of solution (in mL)}}$

Given mass of barium chlorate = 25.0 g

Molar mass of barium chlorate = 304.23 g/mol

Molarity of solution = 0.420 mol/L

Volume of solution = ?

Putting values in above equation, we get:

$0.420mol/L=\frac{25.0\times 1000}{304.23\times V}\\\\V=\frac{25.0\times 1000}{304.23\times 0.420}=195.65mL$

Hence, the volume of barium chlorate is 195.65 mL

6 0

3 years ago

A solution contains 0.036 M Cu2+ and 0.044 M Fe2+. A solution containing sulfide ions is added to selectively precipitate one of

Ratling [72]

Answer:

The precipitate is CuS.

Sulfide will precipitate at [S2-]= 3.61*10^-35 M

Explanation:

Step 1: Data given

The solution contains 0.036 M Cu2+ and 0.044 M Fe2+

Ksp (CuS) = 1.3 × 10-36

Ksp (FeS) = 6.3 × 10-18

Step 2: Calculate precipitate

CuS → Cu^2+ + S^2- Ksp= 1.3*10^-36

FeS → Fe^2+ + S^2- Ksp= 6.3*10^-18

Calculate the minimum of amount needed to form precipitates:

Q=Ksp

For copper we have: Ksp=[Cu2+]*[S2-]

Ksp (CuS) = 1.3*10^-36 = 0.036M *[S2-]

[S2-]= 3.61*10^-35 M

For Iron we have: Ksp=[Fe2+]*[S2-]

Ksp(FeS) = 6.3*10^-18 = 0.044M*[S2-]

[S2-]= 1.43*10^-16 M

CuS will form precipitates before FeS., because only 3.61*10^-35 M Sulfur Ions are needed for CuS. For FeS we need 1.43*10^-16 M Sulfur Ions which is much larger.

The precipitate is CuS.

Sulfide will precipitate at [S2-]= 3.61*10^-35 M

3 0

3 years ago

At the beginning of an experiment, a scientist has 176 grams of radioactive goo. After 165 minutes, her sample has decayed to 5.

Paul [167]

The half-life equation is written as:

An = Aoe^-kt

We use this equation for the solution. We do as follows:

5.5 = 176e^-k(165)
k = 0.02
What is the half-life of the goo in minutes?

0.5 = e^-0.02t
t = 34.66 minutes <----HALF-LIFE

Find a formula for G(t) , the amount of goo remaining at time t.G(t)=?

G(t) = 176e^-0.02t

How many grams of goo will remain after 50 minutes?

G(t) = 176e^-0.02(50) = 64.75 g

6 0

3 years ago

1. What is an indicator and how does it work?​

1. What is an indicator and how does it work?