All categories

3 years ago

A beaker contains 20.0 ml of a 50.0 g/L solution. What will the new concentration be if you add 40.0 mL of water?

Chemistry

1 answer:

Ronch [10]3 years ago

8 0

Answer:

moles SO42- = 0.0500 L x 0.20 M=0.010

moles Ba2+ = 0.0500 L x 0.10 M = 0.0050

Ba2+ + SO42- = BaSO4 (s)

moles SO42- in excess = 0.010 - 0.0050=0.0050

total volume = 100 mL = 0.100 L

[SO42-]= 0.0050/0.100= 0.050 M

[Na2SO4] = 2 /2 = 1 M

moles Na2SO4 = 2 M x 0.500 L = 0.500

mass Na2SO4 = 0.500 x 142 g/mol=71.0 g

moles MgBr2 = 46 /184 =0.25

moles Br- = 0.25 x 2 = 0.50

[Br-]= 0.50 / 0.50 L = 1 M

You might be interested in

Phthalates used as plasticizers in rubber and plastic products are believed to act as hormone mimics in humans. The value of ΔHc

jeka94

Answer:

$T_f$ = 25.05°C

Explanation:

Given:

the value of ΔHcomb (heat of combustion) for dimethylphthalate (C10H10O4) is = 4685 kJ/mol.

mass = 0.905g of dimethylphthalate

molar mass = 194.18g dimethylphthalate

number of moles of dimethylphthalate = ???

$T_i$ = 21.5°C

$C_{calorimeter}$ = 6.15 kJ/°C

$T_f$ = ???

since we have our molar mass and mass of dimethylphthalate ;we can determine the number of moles as;

0.905g of dimethylphthalate × $\frac{1 mole (dimethylphthalate)}{194.184g(dimethylphthalate)}$

number of moles of dimethylphthalate = 0.000466 moles

Heat released = moles of dimethylphthalate × heat of combustion

= 0.000466 moles × 4685 kJ

= 21.84 kJ

∴ Heat absorbed by the calorimeter = $C_{calorimeter}$ $(T_f-T_i} )$

21.84 kJ =6.15 kJ/°C $* (T_f-21,5^0C)$

21.84 KJ = $(6.15 kJ/^0C * T_f) - (6.15 kJ/^0C*21.5^0C)$

21.84 KJ = $(6.15 kJ/^0C * T_f)$ - 132.225 kJ

21.84 KJ + 132.225 kJ = $(6.15 kJ/^0C * T_f)$

154.065 kJ = $(6.15 kJ/^0C * T_f)$

$T_f$ = $\frac{154.065kJ}{6.15kJ/^0C}$

$T_f$ =25.05°C

4 0

3 years ago

Describe the cell cycle?

guajiro [1.7K]

Answer:

Its basically a series of events that take place in a cell. A cell spends most of its time in what is called inter phase, and during this time it grows, replicates its chromosomes, and prepares for cell division. Then after that The cell then leaves interphase, undergoes mitosis, and completes its division.

Explanation:

-Hailey: )

5 0

2 years ago

Which of the following is true?

kotykmax [81]

Anwser is C for cesium

6 0

3 years ago

Read 2 more answers

John roller skates 48 km in 3 hours. What is his average speed in kilometers

Nadya [2.5K]

Answer:16km/hr

Explanation:

48km/3hr= 16km/hr

7 0

3 years ago

Read 2 more answers

The density of water is 1.00 g/ml at 4°c. how many water molecules are present in 2.36 ml of water at this temperature?

spin [16.1K]

Mass of 1 ml of water 1 g as density of water 1.00 g/ml at 4° C. So, mass of 2.36 ml of water $\frac{1}{2.36}$ g= 0.423 g.

Molecular mass of water is 18 g which indicates 18 g water contains 6.023 X $10^{23}$ number of water molecules. So, 0.423 g of water contains $\frac{6.023 X 10^{23} X 0.423 }{18} g$ = 0.141 X $10^{23}$ number of water molecules= 1.41 X $10^{22}$ number of water molecules.

5 0

3 years ago