Which statement best describes the direction of heat flow by conduction between two samples of the same material?

How would each of the following procedural errors affect the results to be expected in this experiment? Give your reasoning in e

Digiron [165]

Answer:

a) if the liquid is not vaporized completely, then the condensed vapor in the flask contains the air which is initially occupied before the liquid is heated. When calculating the molar mass of the vapor the moles of air which are initially present are not excluded, so that the molar mass of the vapor would be an increase in value.

b) While weighing the condensed vapor, the flask should be dried. If the weighing flask is not dried then the water which is layered on the surface of the flask is also added to the mass of the vapor. Therefore, the mass of the vapor that is calculated would be increase.

c) When condensing the vapor, the stopper should not be removed from the flask, because the vapor will escape from the flask and a small amount of vapor will condense in the flask. Therefore, the mass of the condensed vapor would be In small value.

d) If all the liquid is vaporized, when the flask is removed before the vapor had reached the temperature of boiling water, then the boiling

temperature of that liquid would be lower than that of the boiling temperature of the water.Therefore, the liquid may have more volatility.

7 0

2 years ago

How many grams of NH3 can be prepared from the synthesis of 77.3 grams of nitrogen and 14.2 grams of hydrogen gas?

lbvjy [14]

Answer:

80.41 g

Explanation:

Data Given:

Mass of Nitrogen (N₂) = 77.3 g

Mass of Hydrogen (H₂) = 14.2 g

many grams of NH₃ = ?

Solution:

First we look at the balanced synthesis reaction

N₂ + 3 H₂ ------—> 2 NH₃

1 mol 3 mol

As 1 mole of Nitrogen react with 3 mole of hydrogen

Convert moles to mass

molar mass of N₂ = 2(14) = 28 g/mol

molar mass of H₂ = 2(1) + 2 g/mol

Now

N₂ + 3 H₂ ------—> 2 NH₃

1 mol (28 g/mol) 3 mol(2g/mol)

28 g 6 g

28 grams of N₂ react with 6 g of H₂

So

if 28 grams of N₂ produces 6 g of H₂ so how many grams of N₂ will react with 14.2 g of H₂.

Apply Unity Formula

28 g of N₂ ≅ 6 g of H₂

X g of N₂ ≅ 14.2 g of H₂

Do cross multiply

X g of N₂ = 28 g x 14.2 g / 6 g

X g of N₂ = 66.3 g

As we have given with 77. 3 g of N₂ but from this calculation we come to know that 66.3 g will react with 14.2 g of hydrogen and the remaining 10 g N₂ will be in excess

So, Hydrogen is limiting reactant in this reaction and the amount of NH₃ depends on the amount of hydrogen.

Now

To find mass of NH₃ we will do following calculation

Look at the reaction

As we Know

N₂ + 3 H₂ ------—> 2 NH₃

6 g 2 mol

So, 6 g of hydrogen gives 2 moles of NH₃, then how many moles of NH₃ will be produce by 14.2 g

Apply Unity Formula

6 g of H₂ ≅ 2 mol of NH₃

14.2 g of H₂ ≅ X mol of NH₃

Do cross multiply

X mol of NH₃= 14.2 g x 2 mol / 6 g

X mol of NH₃ = 4.73 mol

So, 14.2 g of hydrogen gives 4.73 moles of NH₃

Now

Convert moles of NH₃ to mass

Formula will be used

mass in grams = no. of moles x molar mass . . . . . . (2)

Molar mass of NH₃

Molar mass of NH₃ = 14 + 3(1)

Molar mass of NH₃ = 14 + 3 = 17 g/mol

Put values in equation 2

mass in grams = 4.73 mole x 17 g/mol

mass in grams = 80.41 g

mass of NH₃= 80.41 g

3 0

2 years ago

Use the virtual lab to prepare 150.0 ml of an iodine solution with a concentration of 0.06 g/ ml from the bottle of 0.12g/ml iod

son4ous [18]

Answer:

Explanation:

In 150 ml of .06 g / ml solution , gram of iodine = 150 x .06 g = 9 g

Let volume of given concentration of .12 g / ml required be V

In volume V , gram of iodine = V x .12 g

According to question

V x .12 = 9 g

V = 9 / .12 = 75 ml

So, 75 ml of .12 g/ml will be taken and it is diluted to the volume of 150 ml to get the solution of required concentration .

8 0

2 years ago

Which reactions performed in the experiment involved chemical changes? crushing calcium carbonate mixing calcium carbonate and h

lisov135 [29]

Mixing calcium carbonate and HCl.
Heating copper sulfate pentahydrate.
Mixing potassium iodide and lead nitrate.
Combining magnesium and hcl.
Burning the candle.
Let's look at the available options and see what are chemical changes and what are physical changes. As a side note, line breaks, capitalization, and punctuation are VERY important. I spent almost as much time attempting to actually figure out what your options were as I spent in distinguishing between what were chemical reactions and physical changes.
Crushing calcium carbonate.
* This is a mere physical change. You start with large pieces of calcium carbonate and end up with smaller pieces. So this is a bad choice.
Mixing calcium carbonate and HCl.
* This is a chemical reaction where the calcium carbonate and hydrochloric acid react with each other and produce carbon dioxide plus other compounds. So this is a good choice.
Boiling water.
* Another physical change from liquid to vapor. You can cool down the resulting vapor and end up with the original water. So this is a bad choice.
Heating copper sulfate pentahydrate.
* This is a chemical change in that you're converting CuSO4 . 5H2O(s) into CuSO4 and H2O. So this too is a good choice.
Separating iron filing and sulfur.
* You start out with iron filings and sulfur and end up with iron filings and sulfur. Things are a bit more orderly, but no chemical reactions have occurred. So this is a bad choice.
Mixing potassium iodide and lead nitrate. * You start with 2 white solids and upon mixing them, you get a yellow solid.
A chemical reaction has occurred. So this is a good choice.

Combining magnesium and hcl.
* When you combine these two items, you get hydrogen gas as a product. So you have a chemical reaction. And this is a good choice.
Burning the candle.
* Another chemical reaction. The wax combines with the oxygen in the air and produces water vapor and carbon dioxide. So this is a good choice.

5 0

2 years ago

Read 2 more answers

What is the kinetic energy acquired by the electron in hydrogen atom, if it absorbs a light radiation of energy 1.08x101 J. (A)

Delvig [45]

Explanation:

The given data is as follows.

Energy of radiation absorbed by the electron in hydrogen atom = $1.08 \times 10^{-17} J$