What is the empirical formula for a compound that has 57.5%

Sometimes in lab we collect the gas formed by a chemical reaction over water (see sketch at right). This makes it easy to isolat

ad-work [718]

Answer:

The correct answer is 0.00582 grams.

Explanation:

In order to solve the question, let us consider the vapor pressure of H2O, as hydrogen gas is collected over water, therefore, we have to consider the vapor pressure of water in the given case. Let us assume that the pressure is 760 torr or 1 atm.

It is known that the vapor pressure of water at 40 degree C is 53.365 torr (Based on the data).

Therefore, the pressure of H2 will be,

P = 760-55.365 = 704.635 torr or 704.635/760 = 0.9272 atm

The volume of the hydrogen gas collected in the tube is 80 ml or 0.08 L

Temperature in Kelvin will be 40+273 = 313 K

To calculate the moles of hydrogen (H2) gas, there is a need to use the ideal gas equation, that is, PV= nRT, in this R is the gas constant, whose value is 0.0821 L atm/molK, and n is the moles of the gas.

By inserting the values in the equation we get:

PV = nRT

n = PV/RT = 0.9272 *0.08 / 0.0821 * 313

n = 0.00289 moles

The mass of H2 will be moles * molar mass = 0.00289 * 2.016

= 0.00582 grams.

7 0

3 years ago

Calculate the hydroxide ion concentration [OH-] for a solution with a pH of 6.10

nalin [4]

There are different formula you need to keep in mind when solving for [OH-]

Given that pH = 6.10

pH + pOH = 14

6.10 + pOH = 14

pOH = 7.9

[OH-] = 10^(-pOH)

[OH-] = 10^(-7.9)

[OH-] = 0.000000013

[OH-] = 1.3 x 10^-8

<h2><u>Answer: [OH-] = 1.3 x 10^-8</u></h2>

4 0

3 years ago

How is the oxidation state of a transition metal determined from the chemical formula ?

Vera_Pavlovna [14]

Answer:

Explanation:

In a chemical formula, the oxidation state of transition metals can be determined by establishing the relationships between the electrons gained and that which is lost by an atom.

We know that for compounds to be formed, atoms would either lose, gain or share electrons between one another.

The oxidation state is usually expressed using the oxidation number and it is a formal charge assigned to an atom which is present in a molecule or ion.

To ascertain the oxidation state, we have to comply with some rules:

The algebraic sum of all oxidation numbers of an atom in a neutral compound is zero.
The algebraic sum of all the oxidation numbers of all atoms in an ion containing more than one kind of atom is equal to the charge on the ion.

For example, let us find the oxidation state of Cr in Cr₂O₇²⁻

This would be: 2x + 7(-2) = -2

x = +6

We see that the oxidation number of Cr, a transition metal in the given ion is +6.

7 0

3 years ago

Read 2 more answers

This stadium can hold 100,000, or 1 x 10^5, people. The number of atoms in a grain of iron is about 1 x 10^18. Would you need 1

polet [3.4K]

<h3>Answer:</h3>

1 x 10^13 stadiums

<h3>Explanation:</h3>

From the question;

1 x 10^5 people can fill 1 stadium

We are given, 1 x 10^18 atoms of iron

We are required to determine the number of stadiums that 1 x 10^18 atoms of iron would occupy.

We are going to assume that a stadium would occupy a number of atoms equivalent to the number of people.

Therefore;

One stadium = 1 x 10^5 atoms

Then, to find the number of stadiums that will be occupied by 1 x 10^18 atoms;

No. of stadiums = Total number of atoms ÷ Atoms in a single stadium

= 1 x 10^18 atoms ÷ 1 x 10^5 atoms

= 1 x 10^13 stadiums

Therefore, 1 x 10^18 atoms of iron would occupy 1 x 10^13 stadiums

7 0

3 years ago

3. What do you notice about the temperature of the substance in the test tube after it is placed in the beaker of water?

34kurt

Answer:

C: The temperature of the substance increases as it sits in the beaker of water

Explanation:

This question was taken from a video where an attempt was made to investigate the changes in temperature when a substance undergoes change from it's solid phase to its liquid phase.

To do this, as seen in the video online, it shows a solid substance in a test tube being placed in a beaker of water.

From observation, the water in the beaker has a warmer temperature than the solid substance present in the test tube and this in turn makes the test tube gradually increase in temperature.

Thus, the solid substance will as well increase increase in temperature when it is placed in the beaker of water.

3 0

2 years ago