A 0.227 mol chunk of dry ice (solid CO2) changes to gas. What is the volume of that gas measured at 27 °C and 740 mmHg?

A student pipets 10 ml of a 0.0693 m solution of kbr into a 500 ml volumetric flask and dilutes to the mark. what is the concent

Sonja [21]

The initial concentration of solution is 0.0693 M. The volume of solution taken is 10 mL and it is diluted to a final volume of 500 mL.

According to dilution law, the product of initial concentration and volume is equal to the product of final concentration and volume as follows:

$C_{1}V_{1}=C_{2}V_{2}$

Here, $C_{1}$ is initial concentration, $C_{2}$ is final concentration, $V_{1}$ is initial volume and $V_{2}$ is final volume.

Rearranging to calculate final concentration,

$C_{2}=\frac{C_{1}\times V_{1}}{V_{2}}$

Putting the values,

$C_{2}=\frac{0.0693 M\times 10 mL}{500 mL}=0.001386 M$

Therefore, concentration of the resulting solution is 0.001386 M.

7 0

3 years ago

#7) The atom on the left (pink) in the video is shown in the diagram below. From

ruslelena [56]

Answer:

A

Explanation:

Remember the number of valence electrons represent the group number. As shown in figure, there is only one electron in the valence shell. Therefore, this element belongs to group 1 elements also called as Alkali metals.

Furthermore, the number of electrons in a neutral atom equals number of protons. Hence, there are 11 protons in this element.

Also, number of protons equal atomic number therefore, the atomic number of this element is 11. And, by checking periodic table, the element having atomic number 11 is Sodium (Na).

6 0

3 years ago

QUESTION 6

polet [3.4K]

I would say the answer is C. Mutualism

4 0

3 years ago

Read 2 more answers

URGENT!!!! Please respond in less than 5 mins hurry!!!!?!!?!!??!?

AleksAgata [21]

Answer:

1. A

2. B

Explanation:

1. Most of the answers don't make that much sense, so using process of elimination I resulted in this answer. I recommend you also try to check with others.

2. This question also was pretty confusing but when using process of elimination I resulted in either A or B. To me B makes more sense.

5 0

3 years ago

What is the boiling point of a solution made by adding 6.69 g of magnesium chloride to 250.0 g of water?. Use the formula of the

olya-2409 [2.1K]

Answer:

100.432ºC

Explanation:

Ebullioscopy is the elevation of the boiling point of a solvent that has a solute nonvolatile dissolved. The change in the temperature may be calculated by Raoult's law:

ΔT = Kb.W.i

Where ΔT is the temperature change, Kb is the ebullioscopy constant, W is the molality and i is the Van't Hoff factor, which determinates the particles that affect the proper.

The molality is:

W = m1/(M1xm2)

Where m1 is the solute mass (in g), M1 is the molar mass of the solute, and m2 is the mass of the solvent (in kg).

The Van't Hoff factor is the number of final particles divided by the number of initial particles. Magnesium is from froup 2, so it forms the cation Mg⁺², and chlorine ins from group 7 and forms the anion Cl⁻, the salt is MgCl₂ and dissociates:

MgCl₂ → Mg⁺²(aq) + 2Cl⁻(aq)

So, it has 1 particle in initial, and 3 in final (1 Mg⁺² and 2 Cl⁻). So:

i = 3/1 = 3.

The molar mass of MgCl₂ is: 24.3 + 2x35.5 = 95.3 g/mol, m1 = 6.69g, m2 = 0.250 kg, so:

W = 6.69/(95.3x0.250)

W = 0.281 m

Then:

ΔT = 0.512x0.281x3

ΔT = 0.432ºC

The normal boling point of water is 100ºC, so

T - 100 = 0.432

T = 100.432ºC

6 0

3 years ago