Escaping from the haunted house, Anna ran home immediately to her chemistry lab
back at the high school. After analysis of the gold heart, she found the heart was not
composed of pure gold, but gold (III) oxide (Au203). What percentage (by mass) was
gold in the heart?
a) 10.9% Au
C) 89.1% Au
b) 81.2% Au
d) 92.9% Au

Answers

Answer 1
89.1% Au

The molar mass of Au2O3 is 2(196.97) + 3(16.00) = 441.94 g/mol
The mass percent of Au is therefore 2(196.97) / 441.94, which is 393.94/441.94 = 0.891 —> 89.1%

Related Questions

which do you think will warm up the plate more quickly?

A. Direct sunlight
B.Indirect sunlight

Answers

Answer: B

your welcome Bsbssnsnsmsllqql

Question 25 of 33
Which statement describes a periodie trend of brstionization energy?
A It tends to increase from top to bottom of a group
B. It remains the same within a period
c. It tends to decrease from top to bottom of a group
D. It tends to decrease from left to right across a period

Answers

Answer:

A) It tends to increase from top to bottom of a group

What would you predict to be the valence number and oxidation number of tin?

Answers

Answer:

Tin exists in two oxidation states, +4 and +2. Elemental tin is readily oxidized to the dipositive ion in acidic solution, but this Sn2+ ion is converted to the Sn4+ ion by many mild oxidizing agents, including elemental oxygen. Oxidation under alkaline conditions normally gives the tetrapositive (Sn4+) state.

Please someone help ! I need it ASAP

Answers

Answer:

6.B

7.B

Explanation:

Mark me as brainliest

6b
7b
Are the correct answers

A sample of gas as a volume of 425 mL at 25°C at and 760 tour what volume with this gas sample have at STP

Answers

Answer:

[tex]\Rightarrow V_2 = 389mL[/tex]

Explanation:

To solve this question, we could use Charles' law since both the number of mole and pressure are constant

At STP pressure P = 760 tor and Temperature = 273K

V1 =425mL, T1 =298K and T2 =273K

and [tex]\frac{V_1}{T_1} =\frac{V_2}{T_2}[/tex]

[tex]\Rightarrow V_2 =T_2\times\frac{V_1}{T_1}[/tex]

[tex]\Rightarrow V_2 =273\times\frac{425}{298}[/tex]

Therefore, [tex]\Rightarrow V_2 = 389mL[/tex]

What is the mole ratio of magnesium carbonate to magnesium oxide? MgCO3 →MgO+CO2
a)3:2 b) 1:3 c) 1:1 d) 1:2 e) 2:3

Answers

I think the answer is D

Answer:

d)1:2

Explanation:

if i put regular air into a ziplock bag does carbon dioxide come out?

Answers

Carbon dioxide is released. Because the bag is sealed closed and no air can escape, it inflates like a balloon.

Please answer this accurate!!!

Answers

Answer: Pls these can all cause habitat destruction! Tell your teacher that make her feel s***** because by doing any of those you are either taking away habitats from humans or animals.

calculate the mass of 0.5 moles of caco3 in grams with procedure ​

Answers

Answer:

50g

Explanation:

moalr mass of CaCO3= 40g/mol+ 12g/mol+(16g/mol*3)

                                   =52g/mol+48g/mol

                                   =100g/mol

1 mol= 100g

0.5mol=x

by cross multiplication,

0.5*100gmol=x mol

x=50g

Diamond has a hardness of 10 and chalk a harness of 1. Explain what this means.

Answers

Answer:

they have different forces holding the atoms together

Explanation:

diamond has a strong convalent bond holding the particles together while chalk has weak van der waals forces holding the particles together hence the diffrence in hardness

what color does a green objcet appear under red light

Answers

Answer:

black??

Explanation:

black
hope that helps!

Select the correct answer.
Which unit is used for measuring atomic mass?

AMU-aka
Atomic mass unit

Answers

Answer:

The unit of Atomic mass is "amu"

Explanation:

Atomic mass unit

Is a hydrogel a smart polymer/stimuli-responsive polmer?​

Answers

Polymer scientists have been trying to mimic this behavior by creating so called smart polymers. ... One of the most important classes of stimuli-responsive polymers used for controlled drug delivery is crosslinked polymer networks, e.g., hydrogels and microgels.
Hopefully this helps if not I’ll try rewriting it

Answer:

Polymer scientists have been trying to mimic this behavior by creating so called smart polymers. ... One of the most important classes of stimuli-responsive polymers used for controlled drug delivery is crosslinked polymer networks, e.g., hydrogels and microgels.

Explanation:

zinc crystals is made from zinc Oxide and which acid ​

Answers

Answer:

hydrochloric acid

Explanation:

Zinc oxide will react with hydrochloric acid to form zinc chloride and water.

sulphuric acid

So to make zinc sulphate crystals you add granulated zinc to heated sulphuric acid

Select the correct answer.
Which of the following is true for a heating curve?
Ο Α.
It shows how the pressure of a substance changes when heated.
OB.
It shows how the temperature of a substance changes when heated.
OC.
It shows how the volume of a substance changes when heated.
It shows how the mass of a substance changes when heated.
OD
Reset
Next

Answers

Answer:

the answer is b: it shows how temperature of a substance changes when heated

It showed the temperature of a substance changes when heated

Complete and balance the following neutralization reaction, and estimate the
likely pH of the neutralization point. (3 pts)
Ca(OH)2 + HNO3 →

Answers

Answer:

we have a base-Ca(OH)2 and an acid - HNO3

→Their chemical reaction gives us water and salt Ca(NO3)+ H20 (neutralisation reaction)

the pH is expected to be acidic ... since nitric acid is a strong acid and calcium hydroxide is a weak base .

Explanation:

meet my pets Frankie and Dakota

Question 2
5 pts
The air inside a beach ball is at a temperature of 25°C a pressure of 1.0 atm. The ball
contains 0.85 mol of air, what is its volume?
21 L
27 L
0 171
06.11
< Previous
Nest

Answers

Answer: The volume of given ball is 21 L.

Explanation:

Given : Pressure = 1.0 atm,      no. of moles = 0.85 mol

Temperature = [tex]25^{o}C = (25 + 273) K = 298 K[/tex]

According to the ideal gas equation, formula used is as follows.

PV = nRT

where,

P = pressure

V = volume

n = no. of moles

R = gas constant = 0.0821 L atm/mol K

T = temperature

Substitute the values into above formula as follows.

[tex]PV = nRT\\1.0 atm \times V = 0.85 mol \times 0.0821 Latm/mol K \times 298 K\\V = 21 L[/tex]

Thus, we can conclude that the volume is 21 L.

Which of the following represents an alpha particle?
O A. je
B. He
O C. Y
O D.B

Answers

Answer:

Alpha particle- B. He (Helium 4 atom )

He  represents an alpha particle and the correct option is option B.

What is an alpha particle?

Alpha particles are alternatively known as Alpha radiation or Alpha rays. It is a positively charged particle emitted from the decay of various radioactive materials.

They are emitted from the nucleus of some radionuclides during a form of radioactive decay, called alpha-decay.

Alpha particle mass is due to the two protons and two neutrons bonding.

An alpha-particle is identical to the nucleus of a normal (atomic mass four) helium atom i.e. a doubly ionised helium atom.

Therefore, He  represents an alpha particle and the correct option is option B.

Learn more about Alpha particles, here:

https://brainly.com/question/2288334

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PLEASE HELP HELP ME. THIS IS DUE TODAY PLEASE

Answers

Answer:

5.B 6.A

Explanation:

(sorry if this is short)

What happens when heat is removed from water?

The water particles move farther apart.
The water changes from a liquid to a gas.
The temperature of the water increases.
The kinetic energy of the water particles decreases.

Answers

Answer:

D). The kinetic energy of the water particles decreases.

Explanation:

Your welcome!

ANSWER

D

Explanation: Got it correct on edge 2022

How much does 3 moles of silica weigh

Answers

84.2565

Because

1 silica is equal to 28.0855,

times 3 is 84.2565

One of the main components of an airbag is the gas that fills it. As part of the design process, you need to determine the exact amount of nitrogen that should be produced. Calculate the number of moles of nitrogen required to fill the airbag. Show your work. Assume that the nitrogen produced by the chemical reaction is at a temperature of 495°C and that nitrogen gas behaves like an ideal gas. Use this fact sheet to review the ideal gas law.

Answers

The number of  moles of the gas is 0.016 moles

What is the airbag reaction?

We know that in the airbag, nitrogen gas is obtained by the decomposition of sodium azide as follows; 2NaN3 -----> 2Na + 3N2

Since it is under ideal conditions;

P = 1 atm

V = 1 L

T = 495°C  or 768 K

n = ?

R = 0.082 atm LK-1mol-1

From;

PV= nRT

n = PV/RT

n = 1 atm *  1 L/ 0.082 atm LK-1mol-1 *  768 K

n = 0.016 moles

Learn more about ideal gas law;https://brainly.com/question/13821925

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Somebody look at all the science questions i posted plzzz help ( i will give brainliest

Answers

Answer:

ok

Explanation:

Where are the questions?

A student dissolves 0.112 mol sucrose in enough water to make 4.0 L of solution. What is the molarity of the solution

Answers

Answer: Molarity of the solution is 0.028 M.

Explanation:

Given : Moles of sucrose (solute) = 0.112 mol

Volume of solution = 4.0 L

Molarity is the number of moles of solute dissolved in a liter of solvent.

[tex]Molarity = \frac{no. of moles}{Volume (in L)}\\= \frac{0.112 mol}{4.0 L}\\= 0.028 M[/tex]

Thus, we can conclude that molarity of the solution is 0.028 M.

how has the study of fossil rocks evolved over time? (personal answer)

Answers

Answer:

When an organism dies, it is usually destroyed by other forms of life and by weathering processes. On rare occasions some body parts—particularly hard ones such as shells, teeth, or bones—are preserved by being buried in mud or protected in some other way from predators and weather. Eventually, they may become petrified and preserved indefinitely with the rocks in which they are embedded. Methods such as radiometric dating—measuring the amounts of natural radioactive atoms that remain in certain minerals to determine the elapsed time since they were constituted—make it possible to estimate the time period when the rocks, and the fossils associated with them.

One is a negative environmental consequence of surface mining?

Answers

Answer:

Surface mining (also known as "strip mining") has the potential to significantly erode soil fertility, pollute waters, deplete underground water sources, scar or altar the landscape, damage roads, houses, and other buildings, and kill wildlife.

Floodplains extend from one side of the river valley to the other.
True or False

Answers

Answer:

true

Explanation:

hope this helps!

~mina-san

Answer:

Explanation: true

What the common uses for Rutherfordium???

Answers

Answer:

welcome

Explanation:

Uses of Rutherfordium

Because rutherfordium is made within the lab, there are not very many uses for this element commercially. On the other hand, rutherfordium has been used within the laboratory setting to conduct research. Most elements that are highly radioactive are used for nuclear power and medicinal purposes.

IS ANYONE GOOD AT CHEMISTRY?! like frr.
I need help

Answers

Yeah, what do you need help with?

What are some facts about Radon something that is unique and relatively unknown by the general population???? Helpppppp helpppppp

Answers

Answer: Radon is radioactive

Explanation: thats all i know

Radon as in? Be more specific about your questions and i’d be glad to help youu <3
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