# How many atoms are present in a 1.0 mole sample of potassium perchlorate (KClO3)?

QUESTION POSTED AT 10/10/2019 - 09:38 AM

Okay, a mole of potassium perchlorate contains 6.02x1023 formula units of potassium perchlorate, but you're asking about individual atoms. So, let's look at the formula: KClO3. That's 1 potassium, 1 chlorine, and 3 oxygens, for a total of 5 atoms per formula unit. Now, multiple 5 by Avogadro's number above, to get 30.1x1023, which simplifies to 3.01x1024 atoms.

## Related questions

### 1. Which of the following is a physical change? (2 points) A newspaper burns when placed in a fire. An iron chair rusts when left outside. A sample of water boils and releases gas. A plant changes carbon dioxide and water into sugar.

A.) because it turns from paper to ashes

ANSWERED AT 17/10/2019 - 09:10 AM

QUESTION POSTED AT 17/10/2019 - 09:10 AM

### 1. Which of the following is a physical change? (2 points) A newspaper burns when placed in a fire. An iron chair rusts when left outside. A sample of water boils and releases gas. A plant changes carbon dioxide and water into sugar.

A. It is changing state, color. Etc.

ANSWERED AT 17/10/2019 - 09:09 AM

QUESTION POSTED AT 17/10/2019 - 09:09 AM

### A sample of compressed methane has a volume of 648 mL at a pressure of 503 kPa. To what pressure would the methane have to be compressed in order to have a volume of 216 mL?

To solve this we assume that the gas is an ideal gas. Then, we can use the ideal gas equation which is expressed as PV = nRT. At a constant temperature and number of moles of the gas the product of PV is equal to some constant. At another set of condition of temperature, the constant is still the same. Calculations are as follows:

P1V1 =P2V2

P2 = P1 x V1 / V2

P2 = 503 x 648 / 216

P2 =1509 kPa

ANSWERED AT 17/10/2019 - 09:06 AM

QUESTION POSTED AT 17/10/2019 - 09:06 AM

### Which number is equal to –906,060? –9.0606 mc020-1.jpg 105 –9.06 mc020-2.jpg 105 9.06 mc020-3.jpg 10–5 9.0606 mc020-4.jpg 10–5

the answer is A!!!! why cant some of you ppl just put the letter

ANSWERED AT 17/10/2019 - 09:02 AM

QUESTION POSTED AT 17/10/2019 - 09:02 AM

### Do mechanical waves require a medium to travel through? 10 pts, and explain please.

Yes, because mechanical waves require an initial energy input, and without a medium energy cannot travel.

ANSWERED AT 17/10/2019 - 09:01 AM

QUESTION POSTED AT 17/10/2019 - 09:01 AM

### Relative atomic masses are measured in?

It would be atomic mass units, or amus, if I remember correctly.

ANSWERED AT 17/10/2019 - 08:51 AM

QUESTION POSTED AT 17/10/2019 - 08:51 AM

### True or false: Atoms of the same elements can have different masses

The answer is true hope it helped

ANSWERED AT 17/10/2019 - 08:49 AM

QUESTION POSTED AT 17/10/2019 - 08:49 AM

### Please HELP will give Brainliest!!!!! A solution is made by dissolving 4.0 moles of sodium chloride (NaCl) in 2.05 kilograms of water. If the molal boiling point constant for water (Kb) is 0.51 °C/m, what would be the boiling point of this solution? Show all of the work needed to solve this problem.

4 mol / 205g H2O = 4/.205 = 19.5 mol/kg boiling point = 100 + 19.5 • 0.51 = 109 ºC

ANSWERED AT 17/10/2019 - 08:33 AM

QUESTION POSTED AT 17/10/2019 - 08:33 AM

### An atom of sodium has an atomic mass of 23 and an atomic number of 11. The atom contains 23 protons, 23 electrons, and 11 neutrons. 11 protons, 11 electrons, and 12 neutrons. 11 protons, 12 electrons, and 11 neutrons. 23 protons, 12 electrons, and 23 neutrons.

The second choice, the atomic number plus the number of neutrons equals the atomic mass.

ANSWERED AT 17/10/2019 - 08:06 AM

QUESTION POSTED AT 17/10/2019 - 08:06 AM

### We have a sample of water vapor which cools from 150 C to 125 C what happens to the motion of the molecules during this time of cooling

Any options?????????

ANSWERED AT 17/10/2019 - 08:02 AM

QUESTION POSTED AT 17/10/2019 - 08:02 AM

### Which procedure did early chemists use to determine which substances were elements? A. They observed the way the materials looked. B. They physically broke down the elements they discovered. C. They broke down materials by chemical means. D. They observed the substances that made up individual atoms.

I think the answer is A. They observed the way the elements looked

ANSWERED AT 17/10/2019 - 07:42 AM

QUESTION POSTED AT 17/10/2019 - 07:42 AM

### How many moles of AgNO3 must react to form 0.854 mol Ag?

The equation of its dissolution in water is: AgNO3 → Ag + (aq)  +  NO3- (aq)

and
AgNO3 →   Ag + (aq)  +  NO3- (aq)
1 mol          1mol                1mol
?  --------   0.854mo
so for finding the value, it is sufficients to complute 1 x 0.854 mol =0.854 mol
so,  0.854 mol is required for the reaction to form 0.854 mol of Ag

ANSWERED AT 17/10/2019 - 07:41 AM

QUESTION POSTED AT 17/10/2019 - 07:41 AM

### A drink advertised as having 10% fruit juice has a concentration of 100% by volume of the fruit juice.

It would be 10% concentrated, not 100%

the statement is false

ANSWERED AT 17/10/2019 - 07:22 AM

QUESTION POSTED AT 17/10/2019 - 07:22 AM

### The specific heat of gold is 0.031 calories/gram°C. If 10.0 grams of gold were heated and the temperature of the sample changed by 20.0°C, how many calories of heat energy were absorbed by the sample?

ANSWERED AT 17/10/2019 - 07:15 AM

QUESTION POSTED AT 17/10/2019 - 07:15 AM

### The ksp of pbi2 is 1.4 x 10-8. what is the molar solubility of lead(ii iodide in a solution of 0.400 m sodium iodide?

The solubility product of a substance us calculated by the product of the concentration of the dissociated ions in the solution raise to the stoichiometric coefficient of the ions. Therefore, we need the dissociation reaction. For this, it will have the reaction:

PbI2 = Pb^2+ + 2I-

We solve as follows:

Ksp = [Pb2+][I-]^2 = 1.4 x 10-8
1.4 x 10-8 = x(2x)^2
1.4 x 10-8 = 4x^3
x = 1.5x10^-3 M

The molar solubility would be
1.5x10^-3 M.

ANSWERED AT 17/10/2019 - 06:30 AM

QUESTION POSTED AT 17/10/2019 - 06:30 AM

### Glass is different from a mineral because it ________. select one: a. does not have atoms arranged in an orderly pattern b. is not naturally occurring c. is not a solid d. contains carbon and is therefore organic

The correct answer is A. Glass does not have an orderly arrangement of the atoms, like the minerals. Glass lacks a crystal lattice structure, and is an amorphous solid. The atoms of glass are rigidly fixed but are arranged in an orderly fashion.

ANSWERED AT 17/10/2019 - 06:17 AM

QUESTION POSTED AT 17/10/2019 - 06:17 AM

### From top to bottom in most groups of elements atomic radii tend to

As you go down a group on the periodic table, atomic radii tend to increase because elements with larger atomic numbers have more occupied electron levels which take up more space surrounding the nucleus.

I hope this helps.

ANSWERED AT 17/10/2019 - 05:59 AM

QUESTION POSTED AT 17/10/2019 - 05:59 AM

### If a gas is moved from a large container to a small container but its temperature and number of moles remain the same, what would happen to the pressure of the gas?

The pressure will increase.

ANSWERED AT 17/10/2019 - 05:43 AM

QUESTION POSTED AT 17/10/2019 - 05:43 AM

### What is the minimum number of carbon atoms a ketone may contain

Three. A ketone is a carbonyl compound, meaning there is a carbon oxygen double bond. A ketone is different from an aldehyde as an aldehyde has this C=O at the end of the molecule, while a ketone is on the inside. Thus, there must be a non-terminal carbon for there to be a ketone, and so three carbons are required (minimum), with the C=O at carbon 2.

ANSWERED AT 17/10/2019 - 05:42 AM

QUESTION POSTED AT 17/10/2019 - 05:42 AM

### Bonding atoms that experience large differences in electronegativity values will experience what type of bond? (2 points) Select one: a. ionic b. covalent c. hydrogen d. sharing of electrons

Explanation:

A bond that is formed because of transfer of electrons from one atom to another is known as an ionic bond.

For example, sodium has 1 valence electron and chlorine has 7 valence electrons. So, transfer of one electron from sodium to chlorine will result in an ionic bond leading to the formation of compound NaCl.

Also, there is large difference in electronegativities of a metal and a non-metal. Usually, a metal and a non-metal form an ionic bond.

On the other hand, a bond formed by sharing of electrons is known as a covalent bond.

For example, molecule has covalent bond.

Hence, we can conclude that bonding atoms that experience large differences in electronegativity values will experience ionic bond.

ANSWERED AT 17/10/2019 - 05:40 AM

QUESTION POSTED AT 17/10/2019 - 05:40 AM

### A zinc atom loses 3 electrons to become a zinc ion

Now in total the ion has 27 electrons, 30 protons and 35 neutrons

ANSWERED AT 17/10/2019 - 05:34 AM

QUESTION POSTED AT 17/10/2019 - 05:34 AM

### Nitrogen has an atomic mass of about 14 amu and an atomic number of 7. How many neutrons does nitrogen have?

So the atomic number of an element tells the number of proton in the element.
The atomic mass is the sum of the number of protons and neutrons.

From this we can draw up and equation:
Atomic Mass =  (# of protons)  +  (# of neutrons)

⇒  # of neutrons = Atomic Mass - Atomic Number
= 14  -  7
=  7

Therefore nitrogen has SEVEN neutrons.

ANSWERED AT 17/10/2019 - 05:34 AM

QUESTION POSTED AT 17/10/2019 - 05:34 AM

### The molecular weight of NaCl is 58.44 grams/mole. If you had a 1.0 molar solution (1.0 M), you would have to put 58.44 g of salt in 1.0 liter of solution. How many moles of NaCl would you have in 100 mL of this solution? a. 0.010 b. 0.10 c. 0.58 d. 5.8

Molarity is expressed as the number of moles of solute per volume of the solution. For example, we are given a solution of 2M NaOH this describes a solution that has 2 moles of NaOH per 1 L volume of the solution. To calculate the moles of NaCl in 1.0 M of solution, we simply multiply the volume given of the solution.

moles NaCl = 1.0 M (0.100 L ) = 0.10 mol NaCl --------> OPTION B

ANSWERED AT 17/10/2019 - 05:33 AM

QUESTION POSTED AT 17/10/2019 - 05:33 AM

### A sample liquid is cooled to 150 degree Celsius to 30 degree Celsius, causing the liquid to change into a solid. which of the following occurred?

phase change

happened

ANSWERED AT 17/10/2019 - 05:32 AM

QUESTION POSTED AT 17/10/2019 - 05:32 AM

### A student has a sample of a white powdery substance. She needs to know if it is an ionic compound or a molecular compound. Describe a method she could use to determine what kind of compound the substance is.

She should dissolve it in water and test conductivity. If it conducts electricity it is an ionic compound.

ANSWERED AT 17/10/2019 - 05:29 AM

QUESTION POSTED AT 17/10/2019 - 05:29 AM

### While looking at calcuim (Ca) on the periodic table a student needs to find with a greater atomic mass in the same period.Where should the student look?

To the right of calcium and in the same period.

ANSWERED AT 17/10/2019 - 05:28 AM

QUESTION POSTED AT 17/10/2019 - 05:28 AM

### Calculate the number of moles of carbon dioxide formed when 40.0 moles of oxygen is consumed in the burning of propane. Note the equation is unbalanced. C3H8 + O2 ---> CO2 + H2O : A. 40.0 mol CO2 B. 42.0 mol CO2 C. 20.0 mol CO2 D. 24.0 mol CO2

The first step is to balance the equation:

C3H8 + 5O2 ---> 3CO2 + 4H2O

Check the balance

element          left side        right side

C                    3                  3
H                    8                  4*2 = 8
O                    5*2=10        3*2 + 4 = 10

Then you have the molar ratios:

3 mol C3H8 : 5 mol O2 : 3 mol CO2 : 4 mol H2O

Now you have 40 moles of O2 so you make the proportion:

40.0 mol O2 * [3 mol CO2 / 5 mol O2] = 24.0 mol CO2.

Answer: option D. 24.0 mol CO2

ANSWERED AT 17/10/2019 - 05:22 AM

QUESTION POSTED AT 17/10/2019 - 05:22 AM

### How many moles of sodium hydroxide are needed to make 250 mL of a 3.4 M NaOH solution?

ANSWERED AT 17/10/2019 - 05:14 AM

QUESTION POSTED AT 17/10/2019 - 05:14 AM

### A sample of gas occupies a volume of 50.0 milliliters in a cylinder with a movable piston. The pressure of the sample is 0.90 atm and the temperature is 298K. What is the volume of the sample at STP?

The new volume is 41 mL.
Explanation:
Use the combined gas law
P
1
V
1
T
1
=
P
2
V
2
T
2
.
STP=273.15 K and 1 atm
Given/Known
P
1
=
0.90 atm

V
1
=
50.0 mL

T
1
=
298 K

P
2
=
1 atm

T
2
=
273.15 K
Unknown
V
2
Solution
Rearrange the equation to isolate
V
2
and solve.
P
1
V
1
T
1
=
P
2
V
2
T
2
V
2
=
P
1
V
1
T
2
T
1
P
2
V
2
=
0.90
atm
×
50.0
mL
×
273.15
K
298
K
×
1
atm
=
41 mL

ANSWERED AT 17/10/2019 - 05:10 AM

QUESTION POSTED AT 17/10/2019 - 05:10 AM

### Methane (CH4) reacts with excess oxygen gas (O2) to produce carbon dioxide (CO2) and water (H2O). What is the percent yield of carbon dioxide if the actual yield is 29.8 grams and the theoretical yield is 0.814 moles? 65.6% 71.6% 83.2% 91.4%

83.2%

Explanation:

Percent yield is the ratio of actual yield to the theoretical yield.

Percent yield = actual yield/ theoretical yield x 100

Moles of CO₂ = 0.184 mol

Molar mass of CO₂ = 44 g/mol

Mass of CO₂ = 0.814 mol x 44 g/mol =  35.816 g

Actual yield = 29.8 g

Theoretical yield =    35.816 g

Percent yield = 29.8 g/   35.816 g x 100 = 83.2%

ANSWERED AT 17/10/2019 - 05:08 AM

QUESTION POSTED AT 17/10/2019 - 05:08 AM