All categories

3 years ago

Calculate the mass of NaCl needed to make 40% solution from 3kg of water ? Could you explain step by step please :-)

Chemistry

1 answer:

earnstyle [38]3 years ago

3 0

Ok so 40 percent of 3000 grams which is 3 kg is 1200 grams
So you would need 1.2kg or 1200 grams to make a 40% solution

You might be interested in

Read the selection from the section "Molecules In Motion." The molecules in the hot soup are traveling faster overall than they

Hoochie [10]

Answer: The author used the word "conversely" because the first statement he made is in CONTRAST to the second statement he made.

Explanation:

Matter is made up of atoms or molecules that are in constant motion. The motion of these tiny particles ( molecules) gives the object energy. The movement of these molecules depends on the state of matter which includes

--> GASEOUS STATE: Here, the particles are completely free to move and are always in motion.

--> LIQUID STATE: particles in this state slide by one another and are always in motion.

--> SOLID STATE: particles in this state are held tightly together but are always in motion.

Also, the molecules in motion are greatly affected by temperature changes. Increase in temperature will cause the particles in the liquid to move faster. Such is seen when soup is heated, the molecules travel faster than before. But the OPPOSITE is seen in an ice cube. This is because the ice cube is in solid state and of a lower temperature.

7 0

2 years ago

What is the ph of a 0.25 m solution of c6h5nh2 given that its kb is 1.8 x 10-6?

IrinaK [193]

The pH a 0.25 m solution of C₆H₅NH₂ is equal to 3.13.

<h3>How do we calculate pH of weak base?</h3>

pH of the weak base will be calculate by using the Henderson Hasselbalch equation as:

pH = pKb + log([HB⁺]/[B])

pKb = -log(1.8×10⁻⁶) = 5.7

Chemical reaction for C₆H₅NH₂ is:

C₆H₅NH₂ + H₂O → C₆H₅NH₃⁺ + OH⁻

Initial: 0.25 0 0

Change: -x x x

Equilibrium: 0.25-x x x

Base dissociation constant will be calculated as:
Kb = [C₆H₅NH₃⁺][OH⁻] / [C₆H₅NH₂]

Kb = x² / 0.25 - x

x is very small as compared to 0.25, so we neglect x from that term and by putting value of Kb, then the equation becomes:

1.8×10⁻⁶ = x² / 0.25

x² = (1.8×10⁻⁶)(0.25)

x = 0.67×10⁻³ M = [C₆H₅NH₃⁺]

On putting all these values on the above equation of pH, we get

pH = 5.7 + log(0.67×10⁻³/0.25)

pH = 3.13

Hence pH of the solution is 3.13.

To know more about Henderson Hasselbalch equation, visit the below link:
brainly.com/question/13651361

#SPJ4

5 0

1 year ago

A graduated cylinder is filled to the 40.00-mL mark with a mineral oil. The masses of the cylinder before and after the addition

castortr0y [4]

Answer:

Firstly, Let's experiment this !

Experiment 1 :

159.446g - 124.966g = 34.48g

34.48g = The mass of Mineral oil.

The density of the mineral oil = M/V = 34.48g/40mL = 0.862g/cm³.

Experiment 2 :

124.966 + 18.173 = 143.139 = The mass of solid + cylinder.

124.966 + 50.952 = 175.918 = The mass of solid + cylinder + Mineral water.

175.918 - 143.139 = 32.779 = The mass of added mineral oil.

Explanation:

Now we have to find the volume of the added mineral oil using the density from experiment 1.

V = 32.779g/0.862g/cm³ = 38.02668213mL

Since we found the volume of the solid, we then have to subtract the added mineral oil volume from the total volume from experiment 1.

Volume of solid = 40-38.02668213 = 1.97331787mL

Density of solid = 18.713g/1.97331787mL = 9.483013499g/cm^3

1.97331787 = (4/3)(3.14)r³

1.97331787*(3/4)(3.14) = .4713338861

.4713338861 = r ³

r = 0.7782328425158433

r = 0.78

Now that's our final answer ! r = 0.78

5 0

2 years ago

What is the molecular mass of Br 2?

Kazeer [188]

Answer:

159.808 g/mol

3 0

2 years ago

Read 2 more answers

(Can someone please help me...im literally done with brainly...) Which answer best completes the following sentence? _____ is an

Furkat [3]

Answer:

(1) breaking a pencil (2) rusting of iron

Explanation:

breaking a pencil does not alter the chemical properties of the pencil, it merely breaks it into 2 while the rusting of iron is changing the properties chemically because the iron is oxidizing and reacting with the water and oxygen in the atmosphere

5 0

2 years ago