1) Convert the following:<br> 900g to kg<br><br> 2.87L to uL

A student dissolves of urea in of a solvent with a density of . The student notices that the volume of the solvent does not chan

Dimas [21]

The question incomplete , the complete question is:

A student dissolves of 18.0 g urea in 200.0 mL of a solvent with a density of 0.95 g/mL . The student notices that the volume of the solvent does not change when the urea dissolves in it. Calculate the molarity and molality of the student's solution. Round both of your answers to significant digits.

Answer:

The molarity and molality of the student's solution is 1.50 Molar and 1.58 molal.

Explanation:

Moles of urea = $\frac{18.0 g}{60 g/mol}=0.3 mol$

Volume of the solution = 200.0 mL = 0.2 L (1 mL = 0.001 L)

$Molarity(M)=\frac{\text{Moles of compound}}{\text{Volume of solution in L}}$

Molarity of the urea solution ;

$M=\frac{0.3 mol}{0.200 L}=1.50 M$

Mass of solvent = m

Volume of solvent = V = 200.0 mL

Density of the urea = d = 0.95 g/mL

$m=d\times V=0.95 g/mL\times 200.0 mL=190 g$

$m = 190 g = 190 \times 0.001 kg = 0.19 kg$

(1 g = 0.001 kg)

Molality of the urea solution ;

$Molality(m)=\frac{\text{Moles of compound}}{\text{Mass of solvent in kg}}$

$m=\frac{0.3 mol}{0.19 kg}=1.58 m$

The molarity and molality of the student's solution is 1.50 Molar and 1.58 molal.

7 0

3 years ago

PLS HELP ASAP!! Why is titanium known as a strategic metal??

Rom4ik [11]

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Titanium is known as a strategic metal because it is one of the most abundant items on Earth! Also, it is used to build structures, such as space crafts, aircrafts, etc.

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Hope this helps!

7 0

3 years ago

True or False: In a compound, the combination of elements is always different

dmitriy555 [2]

Answer:

in some cases this is true a compound is a mixture of elements although it is actualy false the diffrence is actualy baced on what elements it is made of like sulfur Dioxide is when sulfur reacts with the contents of the air when burning and reacting but they arnt always diffrent most caces it is just what element you use.

Explanation:

7 0

3 years ago

Anh measured the temperature of a pond near his house. Before he left for school, the water in the pond was 18 degrees celsius.

Hitman42 [59]

As the temperature increases, B) the molecules started moving faster.

Explanation:

The temperature of a substance is a measure of the average kinetic energy of the particles in a substance. In particular, it can be found that the temperature is directly proportional to the average kinetic energy of the particles:

$T\propto KE$

The kinetic energy of a particle is given by

$KE=\frac{1}{2}mv^2$

where

m is the mass of the particle

v is its speed

This means that the higher the temperature of a substance, the greater the speed of the particles in the substance.

Therefore, if we apply this concept to this problem, we infer that as the temperature of the water in the pond gets higher, the speed of the molecules inside the water increases, which means that the molecules are moving faster.

Therefore, the correct answer is

B) the molecules started moving faster.

Learn more about temperature:

brainly.com/question/1603430

brainly.com/question/4370740

#LearnwithBrainly

3 0

4 years ago

Is the dissolution of borax endothermic or exothermic.

Olin [163]

Answer: Endothermic.

Explanation: ...