All categories

2 years ago

How much heat is required to raise the temperature of 18 grams of liquid water by 25 C?

1 answer:

3 0

Since the molecular weight of water is about 18 g/mol, you have about 1 mol of water. So, now we know that it takes approximately 46.2 kJ of heat energy to warm 18.02g of water from 25C to 100C and then to vaporize it into steam. Hopefully this helped!

Explanation:

You might be interested in

What are the 5 ways to identify if a chemical reaction happened?

vlada-n [284]

Answer:

a new substance is formed, if heat is formed, color change, the evolution of gas, and bubbles or fizzing

7 0

3 years ago

An aqueous CsCl solution is 8.00 wt% CsCl and has a density of 1.0643 g/mL at 20°C. What is the boiling point of this solution?

umka2103 [35]

<u>Answer:</u> The boiling point of solution is 100.53

<u>Explanation:</u>

We are given:

8.00 wt % of CsCl

This means that 8.00 grams of CsCl is present in 100 grams of solution

Mass of solvent = (100 - 8) g = 92 grams

The equation used to calculate elevation in boiling point follows:

$\Delta T_b=\text{Boiling point of solution}-\text{Boiling point of pure solution}$

To calculate the elevation in boiling point, we use the equation:

$\Delta T_b=iK_bm$

Or,

$\text{Boiling point of solution}-\text{Boiling point of pure solution}=i\times K_b\times \frac{m_{solute}\times 1000}{M_{solute}\times W_{solvent}\text{ (in grams)}}$

where,

Boiling point of pure solution = 100°C

i = Vant hoff factor = 2 (For CsCl)

$K_b$ = molal boiling point elevation constant = 0.51°C/m

$m_{solute}$ = Given mass of solute (CsCl) = 8.00 g

$M_{solute}$ = Molar mass of solute (CsCl) = 168.4 g/mol

$W_{solvent}$ = Mass of solvent (water) = 92 g

Putting values in above equation, we get:

$\text{Boiling point of solution}-100=2\times 0.51^oC/m\times \frac{8.00\times 1000}{168.4g/mol\times 92}\\\\\text{Boiling point of solution}=100.53^oC$

Hence, the boiling point of solution is 100.53

6 0

3 years ago

Ethanol (c2h6o) is a common intoxicant and fuel produced from the fermentation of various grains. how many moles of ethanol are

Lynna [10]

n = m / M

Where, n is moles of the compound (mol), m is the mass of the compound (g) and M is the molar mass of the compound (g/mol)

Here, the given ethanol mass = 50.0 kg = 50.0 x 10³ g

Molar mass of the ethanol = (12 x 2 + 1x 6 + 1 x 16) g/mol
= 46 g/mol

Hence, moles in 50.0kg of ethanol = 50.0 x 10³ g / 46 g/mol
= 1086.96 mol

3 0

2 years ago

What is the atomic mass/mass number of the atom in the diagram above?

Lelechka [254]

Answer:

the atomic number is 5

the atomic mass is 11

Explanation:

The atomic number is the amount of protons inside the nucleus, and this number also equals the amount of electrons. Since it shows you the nucleus and the electrons, all you need to do is count the protons (positive charge inside the nucleus) or count all the electrons (negative charge outside the nucleus, in the rings) and you should have your atomic number.

As for mass, all you need to do is count all the protons and neutrons inside the nucleus and add them up. Protons = 5, Neutrons = 6. (you add them since the equation for atomic mass is Atomic Mass = Protons + neutrons. This works every time)

5+6= 11, so your atomic mass is 11

I hope this helps :)

3 0

1 year ago

Someone answer this please.

Nataly_w [17]

Answer: The percent composition of oxygen is 54.5%

Explanation:

Below I have attached my work through, but essentially the percent composition relies on finding the mass of the oxygens and dividing it by the mass of the whole compound. The masses of the elements can be found on the periodic table and added together to get a mass of the whole compound- ascorbic acid. Then, you turn this proportion into a percent by multiplying by 100%.

6 0

3 years ago

Read 2 more answers