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3 years ago

What is the molality of the solution?

Chemistry

1 answer:

castortr0y [4]3 years ago

7 0

Answer:

6.6023g

Explanation:

To create a 0.247 M solution required weight of barium hydroxide.

0.247 x 171.346 =42.322g per liter

Therefore required mass for 156g of water = 42.322 x 0.156 = 6.6023g

You might be interested in

Charcoal found under a stone at Stonehenge, England, has a carbon-14 activity that is 0.60 that of new wood. How old is the char

kenny6666 [7]

Charcoal with a carbon-14 activity of 0.60 compared to new wood has less than 5,730 years.

<h3>What is a radioactive isotope?</h3>

A radioactive isotope is an element in nature that emit radioactivity in a given period of time (e.g., the half-life for C14 is equal to 5,730 years).

Radioactive dating is a technique to measure the age of an element by measuring its radioactive activity.

In conclusion, charcoal with a carbon-14 activity of 0.60 compared to new wood has less than 5,730 yr.

Learn more about radioactive dating here:

brainly.com/question/8831242

#SPJ1

5 0

2 years ago

Find the molar mass of 2Cu (NO3)2

8090 [49]

Answer:

187.5558 mol

Explanation:

7 0

3 years ago

Suppose you have 81.8 g of Cd. How many Cd atoms are present? Report your answer in scientific notation using the format of 6.02

Lostsunrise [7]

Answer:

1. number of Cd atoms = 4.384 × 10²³

2. number of moles of Ti = 0.817 mol

3. molar mass of C₇H₆O₃ = 138.077 g/mol

4. moles of Sildenafil = 0.249 mmol

Explanation:

1. given data

mass of Cd = 81.8 g

number of Cd atoms = ?

molar mass of Cd = 112.411 g/mol

Solution

1st we find out the number of moles of Cd

number of moles = mass / molar mass

number of moles of Cd = 81.8 g / 112.411 g.mol⁻

number of moles of Cd = 0.728 mol

Now we find out the number of Cd atoms

number of atoms = moles × 6.022 × 10²³

number of Cd atoms = 0.728 (6.022 × 10²³)

number of Cd atoms = 4.384 × 10²³

2. Given data

Mass of Ti = 39.1 g

moles = ?

molar mass Ti = 47.867 g/mol

Solution

Now we will find out the number of moles

number of moles = mass / molar mass

number of moles of Ti = 39.1 g / 47.867 g.mol⁻

number of moles of Ti = 0.817 mol

3. Given data

chemical formula of Salicylic acid = C₇H₆O₃

molar mass of salicylic acid = ?

molar mass of carbon = 12.011

molar mass of hydrogen = 1.008

molar mass of oxygen = 15.999

molar mass of molecule = number of moles of atoms × molar mass of atoms

molar mass of C₇H₆O₃ = 7 (12.011) + 6 (1) + 3 (16)

molar mass of C₇H₆O₃ = 84.077 g + 6 g + 48 g

molar mass of C₇H₆O₃ = 138.077 g/mol

4. Given data

molar mass of Sildenafil = 474.5828 g/mol

mass given = 0.118 g

moles of Sildenafil = ?

Solution

Now we find out the number of moles

number of moles = mass / molar mass

number of moles Sildenafil = 0.118 g / 474.5828 g/mol

number of moles Sildenafil = 0.0003 mol

as this is very small amount we convert it into millimoles

millimoles = moles × 1000

millimoles of Sildenafil = 0.000249 × 1000

millimoles of Sildenafil = 0.249 mmol

4 0

3 years ago

Lighters are usually fueled by butane (c4h10). when 1 mole of butane burns at constant pressure, it produces 2658 kj of heat and

Leokris [45]

Answer:

ΔE = -2661 KJ/mole

ΔH = -2658 KJ/mole

Explanation:

ΔH = q - PΔV

ΔE = q + w

First, to find ΔE:

The reaction PRODUCES 2658 kJ of h (q), and does 3 kJ of work (w).

2658 kJ(q) + 3 kJ(w) = 2661 kJ, BUT the reaction PRODUCES heat, which means ΔE is negative.

ΔE = -2661 KJ/mole

Second, to find ΔH:

ΔH = q - PΔV

ΔH = 2658 kJ(q) - PΔV

Now, the question states that butane burns at a constant pressure; that just translates to the pressure of the reaction is equal to 0.

ΔH = 2658 KJ(q) - (0)ΔV

ΔH = 2658 KJ - 0

ΔH = 2658 kJ, BUT, like before, the reaction PRODUCES heat, which also mean ΔH is negative.

ΔH = -2658 KJ/mole

I hope this helped! Have a nice week.

5 0

3 years ago

Use the following picture to answer questions #6 and 7. Consider that after the snowboarder starts down from the hill from point

STALIN [3.7K]

Remeber:

Kinectic energy = [1/2]mv^2
Potential energy = m.g[h - h0]

6. When the snowboarder is still at the top, she does not have kinetic energy, given that the speed is zero.

There, at the top, the potential energy is maximum, given that the height, h - h0, is the highest.

So, ar the topo she only has potential energy.

7. From that point, the snowboarder, starts to gain velocity; is has started a process of conversion of potential energy to kinetic energy. More velocity, less height, more kinetic ener energy and less ptential energy.

At the very bottom, when she has reached the heigth of reference, h0, the term [h - h0] becomes zero, then the potential energy has dissapeared and all the energy has been transformed into kinetic energy; the speed and the kinetic energy are maximum.

4 0

3 years ago