13. Due to changes in energy, substances can change their state of matter. When

Scientific knowledge results from the interaction of scientists who are investigating natural phenomena. Which of these BEST des

seraphim [82]

Answer:

5ywhxhghghghfhffgffgffg

Explanation:

6 0

2 years ago

A flask containing helium gas is connected to an open-ended mercury manometer. The open end is exposed to the atmosphere, where

stepladder [879]

Answer:

726 torr

Explanation:

Generally, atmospheric pressure can be measured using a manometer which is in form of a U-shaped tube. In addition, 1 mm Hg is equivalent to 1 torr. Therefore, 752 torr is equivalent to 752 mm Hg. Therefore, the total pressure will be equivalent to the atmospheric pressure (mm Hg) + the mercury height.

In this case, the mercury height = -26 mm

Thus:

The helium pressure = 752 - 26 = 726 mm Hg

This is also equivalent to 726 torr

8 0

3 years ago

The net ionic equation for the precipitation reaction that occurs when aqueous solutions of silver(i) nitrate and chromium(iii)

eduard

The net ionic equation formed is

Ag^+(aq)+Cl^−(aq)→AgCl(s)

Chromium(III) nitrate and silver(I) chloride are the products of the balanced molecular equation for the reaction between chromium(III) chloride and silver(I) nitrate. An (s) next to the chemical formula for silver(I) chloride designates it as an insoluble salt.

CrCl3(aq)+3AgNO3(aq)→Cr(NO3)3(aq)+3AgCl(s)

Silver and the chloride ions are the two ions that must interact to create silver(I) chloride. By designating ions as the reactants and silver(I) chloride as the product, the net ionic equation is formed.

Ag^+(aq)+Cl^−(aq)→AgCl(s)

Ionic Equation:

In general, anions and cations react to generate a compound in a dissolved media, which is known as an ionic reaction. Water-insoluble salts are created when the ions of water-soluble salts interact with one another in an aqueous media.

To learn more about Ionic equaion click the given link

brainly.com/question/19705645

#SPJ4

3 0

1 year ago

Which of the following sign does not indicate that a chemical change has happened .

Sever21 [200]

Answer:

A.)

Explanation:

A change in state may seem like a chemical reaction, but it is actually a physical change. "A change in state" is basically saying that the appearance of whatever the item is, is taking a change physically. Whether this item was going through some examples of a physical change, which would be:

<em>melting (solid to liquid), evaporation (liquid to gas), condensation (gas to liquid), freezing (liquid to solid), deposition (gas to solid), and sublimation (solid to gas).</em>

A change in color, odor, taste, chemical compound, and temperature all represent a chemical reaction, because these are all things that are happening within the the item that is being given the product of a chemical change.

Think of it this way: <em>internal changes within the product: chemical. External changes within the product: physical.</em>

I hope this helps.

4 0

2 years ago

A chemist uses hot hydrogen gas to convert chromium(III) oxide to

Darya [45]

Answer: 3.024 g grams of hydrogen are needed to convert 76 grams of chromium(III) oxide, $Cr_{2}O_{3}$

Explanation:

The reaction equation for given reaction is as follows.

$Cr_{2}O_{3} + 3H_{2} \rightarrow 2Cr + 3H_{2}O$

Here, 1 mole of $Cr_{2}O_{3}$ reacts with 3 moles of $H_{2}$ .

As mass of chromium (III) oxide is given as 76 g and molar mass of chromium (III) oxide $(Cr_{2}O_{3})$ is 152 g/mol.

Number of moles is the mass of substance divided by its molar mass. So, moles of $Cr_{2}O_{3}$ is calculated as follows.

$No. of moles = \frac{mass}{molar mass}\\= \frac{76 g}{152 g/mol}\\= 0.5 mol$

Now, moles of $H_{2}$ .given by 0.5 mol of $Cr_{2}O_{3}$ is calculated as follows.

$0.5 mol Cr_{2}O_{3} \times \frac{3 mol H_{2}}{1 mol Cr_{2}O_{3}}\\= 1.5 mol H_{2}$

As molar mass of $H_{2}$ is 2.016 g/mol. Therefore, mass of $H_{2}$ is calculated as follows.

$No. of moles = \frac{mass}{molar mass}\\1.5 mol = \frac{mass}{2.016 g/mol}\\mass = 3.024 g$

Thus, we can conclude that 3.024 g grams of hydrogen are needed to convert 76 grams of chromium(III) oxide, $Cr_{2}O_{3}$ .

7 0

3 years ago