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3 years ago

Problem 1: For which of the following activities might you want to hire a chemist?

1 answer:

3 0

<span>Problem 1) From the given options the one that is proper of a chemist is the option B. testing a sample of water form a well. This activity belongs to the field called analytical chemistry which uses special techniques (instruments and processes) to study (separate, identify and quantify matter).
Problem 2) The only of the given procedures that involves a physical change in one substance is the option D. grinding chalk into a fine powder. In this process the molecules remain being the same (same atoms bonded in the number and way).</span>

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How many milliliters of nitrogen, N2, would have to be collected at 99.19 kPa and 28oC to have a sample containing 0.015 moles o

Semmy [17]

Answer:

378mL

Explanation:

The following data were obtained from the question:

Pressure (P) = 99.19 kPa

Temperature (T) = 28°C

Number of mole (n) = 0.015 mole

Volume (V) =...?

Next, we shall convert the pressure and temperature to appropriate units. This is illustrated below:

For Pressure:

101.325 KPa = 1 atm

Therefore, 99.19 kPa = 99.19/101.325 = 0.98 atm

For Temperature:

T(K) = T(°C) + 273

T(°C) = 28°C

T(K) = 28°C + 273 = 301K.

Next we shall determine the volume of N2. The volume of N2 can be obtained by using the ideal gas equation as shown below:

PV = nRT

Pressure (P) = 0.98 atm

Temperature (T) = 301K

Number of mole (n) = 0.015 mole

Gas constant (R) = 0.0821atm.L/Kmol.

Volume (V) =...?

0.98 x V = 0.015 x 0.0821 x 301

Divide both side by 0.98

V = (0.015 x 0.0821 x 301) /0.98

V = 0.378 L

Finally, we shall convert 0.378 L to millilitres (mL). This is illustrated below:

1L = 1000mL

Therefore, 0.378L = 0.378 x 1000 = 378mL

Therefore, the volume of N2 collected is 378mL

4 0

3 years ago

A 25 kg rock is placed in a graduated cylinder with water.the volume of the fluid is 18.3ml.calculate the density of the rock in

ipn [44]

Answer:

=> 1366.120 g/mL.

Explanation:

To determine the formula to use in solving such a problem, you have to consider what you have been given.

We have;

mass (m) = 25 Kg

Volume (v) = 18.3 mL.

From our question, we are to determine the density (rho) of the rock.

The formula:

$p = \frac{m}{v}$

First let's convert 25 Kg to g;

1 Kg = 1000 g

25 Kg = ?

$= \frac{25 × 1000}{1}$

= 25000 g

Substitute the values into the formula:

$p = \frac{25000 g}{18.3 ml}$

= 1366.120 g/mL.

Therefore, the density (rho) of the rock is 1366.120 g/mL.

8 0

2 years ago

Which of the following sequences of elements would all have four valence electrons?

timama [110]

Answer:b

Explanation:

8 0

3 years ago

Write the name and molecular formula of an organic compounds having its name suffixed with -ol and having 2 carbon atoms in the

777dan777 [17]

Ethanol C₂H₆O

Explanation:

When ethanol (CH₃-CH₂-OH) is heated in the presence of the sulphuric acid (H₂SO₄) it will produce ethylene (CH₂=CH₂ ) and water (H₂O).

CH₃-CH₂-OH → CH₂=CH₂ + H₂O

Learn more about:

sulphuric acid

brainly.com/question/867125

#learnwithBrainly

4 0

3 years ago

Converting carbon to nitrogen by increasing the number of protons from 6 to 7 and decreasing the number of neutrons from 8 to 7

Anton [14]

this is beta decay as the mass number stays the same but proton number changes, this is specifically beta minus as a neuron changes into a proton

4 0

3 years ago

Read 2 more answers