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2 years ago

what is the concentration in ppm of a solution which is prepared by dissolving in 15mg of nacl in 200ml water

Chemistry

1 answer:

bezimeni [28]2 years ago

6 0

Answer:

Explanation:

In weight/volume (w/v) terms,

1 ppm = 1g m-3 = 1 mg L-1 = 1 μg mL-1

200 mL = 0.2 L

15 / 0.2 mg L-1 =75 ppm

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Why do elements that make positive ions occur on the left side of the periodic table while those that make negative ions occur o

Lynna [10]

Answer:

Elements in the same group have the same number of valence electrons.

Explanation: Science.

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3 years ago

A wooden artifact from an ancient tomb contains 60% of the carbon-14 that is present in living trees. How long ago was the artif

noname [10]

Answer:

The age of the sample is 4224 years.

Explanation:

Let the age of the sample be t years old.

Initial mass percentage of carbon-14 in an artifact = 100%

Initial mass of carbon-14 in an artifact = $[A_o]$

Final mass percentage of carbon-14 in an artifact t years = 60%

Final mass of carbon-14 in an artifact = $[A]=0.06[A_o]$

Half life of the carbon-14 = $t_{1/2}=5730 years$

$k=\frac{0.693}{t_{1/2}}$

$[A]=[A_o]\times e^{-kt}$

$[A]=[A_o]\times e^{-\frac{0.693}{t_{1/2}}\times t}$

$0.60[A_o]=[A_o]\times e^{-\frac{0.693}{5730 year}\times t}$

Solving for t:

t = 4223.71 years ≈ 4224 years

The age of the sample is 4224 years.

8 0

3 years ago

A compound is broken down by chemical means during

alexandr1967 [171]

Answer : Option 3) Electrolysis.

Explanation : In the process of electrolysis, decomposition of the chemical is done by passing the electric current from the liquid or the solution containing ions in it. This is the process where compound is broken into ions namely, cations and anions.

Rest all options does not involves chemical decomposition of the compound.

Chromatography is a technique where rates of solute and solvent are compared in a medium where the solute components move at different rates and the separation is obtained.

Distillation simply purifies the liquid or solution by heating or cooling process.

Filtration just involves removal of impurities by using a more porous material device to get purified compound.

6 0

2 years ago

Read 2 more answers

How do you convert from grabs to moles of a substance

Lorico [155]

The correct question is as follows:

How do you convert from grams to moles of a substance

1. Divide by the molar mass

2. Subtract the molar mass

3. Add the molar mass

4. Multiple by the molar mass

Answer: In order to convert from grams to moles of a substance divide by the molar mass.

Explanation:

The number of moles of a substance is the mass of substance in grams divided by its molar mass.

The formula to calculate moles is as follows.

$Moles = \frac{mass}{molar mass}$

This means that grams are converted to moles when grams is divided by molar mass.

Thus, we can conclude that in order to convert from grams to moles of a substance divide by the molar mass.

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3 years ago

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alexandr402 [8]

What do you mean by not drawing?

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2 years ago