Two experiments were conducted: 4.125 g of copper(II) oxide, CuO2, was reduced by heating at high pressure with excess hydrogen to yield 3.294 g of copper Cu. 1.179 g of copper Cu was dissolved in nitric acid to yield copper(II) nitrate, which was converted to 1.476 g copper(II) oxide, CuO2, on ignition. Show that the results illustrate the law of definite proportions by calculating the percentage of oxygen in copper(II) oxide in experiments 1 and 2.

Answers

Answer 1

Answer:

Explanation:

4.125 g of copper oxide contains 3.294 g of Cu . Rest is oxygen

oxygen is 4.125 - 3.294 = .831 g

Ratio of oxygen and copper = .831 : 3.294

.831 / .831 : 3.294 / .831

= 1 : 3.96

1 : 4 ( Approx )

percentage of oxygen in copper oxide = 20 % approx

in the second experiment ,

1.476 g of copper oxide is formed from 1.179 g of Cu

oxygen in this copper oxide = 1.476 - 1.179 = .297 g

Ratio of oxygen and copper

.297 : 1.179

.297/.297 : 1.179/ .297

1 : 3.96

1 : 4 ( approx )

percentage of oxygen in copper oxide = 20 % approx

So it follows the law of definite proportions .


Related Questions

Just like cans of soup, atoms of the same element often have different masses. These different varieties are called isotopes. In the Average Atomic Mass Gizmo, you will learn how to find the average mass of an element using an instrument called a mass s

Answers

Answer:

ions are deflected and the lighter the ions the more the deflection.

Placing magnetic field in the path of the ions cause them to move in a curved path.

Explanation:

This question is all about the way in which mass spectroscopy works. Mass spectroscopy Is one of the techniques in spectroscopy which is used in the identification of chemical compounds.

Mass spectroscopy works based on the principle of ionization. For a mass spectroscopy to start ionization must first occur that is to say this is the first step in the identification of compound in mass spectroscopy.

The following steps are involve in mass spectroscopy;

=> Ionization: the molecules of the sample are first ionized. The ions formed here are positive ions.

=> Acceleration: the ions in step one are accelerated.

=> Deflection: the smaller ions get deflected more than the bigger ions. The magnetic field is used in the deflection of this ions.

=> Detection: the ions are then detected.

Therefore, to answer the question, the ions are deflected and the lighter the ions the more the deflection.

Placing magnetic field in the path of the ions cause them to move in a curved path.

5. A reaction in which them material that starts the reaction is also one of the products and can start another reaction is called

a. An accelerator reaction
b. A moderator reaction
c. A shielding reaction
d. A chain reaction

Answers

Answer:

chain reaction

Explanation:

A chain reaction is a sequence of reactions where a reactive product or by-product causes additional reactions to take place.

How many grams of silver nitrate are needed to prepare 0.125 M solution in 250.0 mL of water?*
(1 Point)
AgNO₃
Ag
= 107.868 8
mol
N = 14.0078
mol
8
0 = 15.999
mol
0.313 g
169.872 g
0.0849 g
5.31 g
O 31.3 g

Answers

Answer:5.3 grams AgNO3

Explanation:

To solve your problem, take a look at the definition of molality (m):

moles of solute/kg of solvent

You are given the grams of solvent (water) to find the grams of silver nitrate.

First, convert 250 grams to kg:

250 g * 1 kg / 1000g = 0.250 kg

Now that you have the kg of solvent, you can solve for the moles of solute:

kg of solvent * molality = moles of solute

0.250 kg * 0.125 m = 0.03125 mol AgNO3

You can convert the number of moles to grams using the molar mass of AgNO3, which is 169.872 g/mol:

moles of solute * molar mass of solute = grams of solute

0.03125 mol AgNO3 * 169.872 g/mol = 5.3085 g

Because your question provides two significant digits, you must round this number to get the final answer:

5.3 grams AgNO3

I hope this helps!

A silver nitrate solution contains 14.77 g of primary standard AGNO3 ( Molecular weight 169.87) in 1.00 L. What volume of this solution will be needed to react with 0.2631 g of NaCl ( Molecular weight 58.44) ?

Answers

Answer:

[tex]V=5.2 mL=0.052L[/tex]

Explanation:

Hello!

In this case, since the chemical reaction between silver nitrate and sodium chloride is:

[tex]AgNO_3(aq)+NaCl(aq)\rightarrow AgCl(s)+NaNO_3(aq)[/tex]

We can see there is a 1:1 mole ratio between each solution; thus, we first compute the moles of each reactant considering their molar masses:

[tex]n_{AgNO_3}=14.77g*\frac{1mol}{169.87g}=0.087molAgNO_3\\\\ n_{NaCl}=0.2631g*\frac{1mol}{58.44}=0.0045molNaCl[/tex]

Now, since the concentration of the silver chloride solution is 0.087 M, we may assume that the concentration of the NaCl solution is the same, so we can compute the volume as shown below:

[tex]V=\frac{n_{NaCl}}{M}=\frac{0.0045mol}{0.087mol/L}\\\\V=0.052L[/tex]

Or:

[tex]V=5.2 mL[/tex]

Best regards!

The volume of solution needed to react with 0.2631 g of NaCl  is 0.052 L.

How we calculate the volume?

Volume of the solution will be calculated by using the below formula:

M = n/V, where

M = concentration in terms of molarity

n = no. of moles

V = volume

Given chemical reaction is:

AgNO₃(aq) + NaCl(aq) → AgCl(s) + NaNO₃(aq)

First we calculate the moles of given reactants by using the formula:

n = W/M , where

W = given mass

M = molar mass

Moles of AgNO₃ = 14.77g / 169.87g/mole = 0.087 mole

Moles of NaCl = 0.2631g / 58.44g/mole = 0.0045 mole

Concentration of AgNO₃ = 0.087 mole / 1L = 0.087M

From the stoichiometry of the reaction it is clear that mole ration of AgNO₃ & NaCl is 1:1. So, we take the concentration of NaCl is equal to the concentration of AgNO₃ and calculate the volume by using the above formula as:

Volume of NaCl = 0.0045mole / 0.087M = 0.052 L

Hence, 0.052 L is the required volume of NaCl.

To know more about moles, visit the below link:

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Why does adding lemon juice to a blueberry smoothie
make it change color from purple to pink.

Answers

Answer:

Acidity

Explanation:

Match the following elements with their symbols.

1.mercury Ag
2.silver He
3.gold Al
4.aluminum Fe
5.iron Hg
6.helium Ca
7.calcium Au
8.magnesium Mg
9.nickel Ni

Answers

1: Mercury - Hg
2: Silver - Ag
3: Gold - Au
4. Aluminium - Al
5: Iron - Fe
6: Helium - He
7: Calcium - Ca
8: Magnesium - Mg
9: Nickel - No

Match the following elements with their symbols.

[tex] \sf 1.\: mercury \: \: \: \: \: \: \: \: \: Ag (2)\\ \sf 2.\: silver \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: He (6) \\ \sf 3.\: gold \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: Al (4) \\ \sf 4.\: aluminum \: \: \: \: \: \: \: Fe (5) \\ \sf 5.\: iron \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: Hg (1)\\ \sf 6.\: helium \: \: \: \: \: \: \: \: \: \: \: \: Ca (7) \\ \sf 7.\: calcium \: \: \: \: \: \: \: \: \: \: Au (3)\\ \sf 8.\: magnesium \: \: \: Mg(8) \\ \sf 9.\: nickel \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: Ni(9) \\ [/tex]

_____________________________

Symbol of Mercury is Hg.Symbol of Silver is Ag.Symbol of gold is Au.Symbol of Aluminium is Al.Symbol of Iron is Fe.Symbol of Helium is He.Symbol of Calcium is Ca.Symbol of Magnesium is Mg.Symbol of Nickel is Ni.

The density of copper is a...

a. chemical property
c. chemical change
b. physical property
d. physical change

Answers

Answer:

B. physical property is the answer

A continuously stirred tank reactor is designed to remove the hazardous waste compound trichloroethylene (TCE) from industrial wastewater. The tank is 3250 liters. The wastewater flows into the tank at 200 L/min with a TCE concentration of 25 mg/L. The reactor decays TCE at a reaction rate of 0.20 min-1 . What is the steady-state concentration of TCE in the treated water leaving the reactor

Answers

Answer:

the steady-state concentration of TCE in the treated water leaving the reactor is 5.88 mg/L  

Explanation:

Given that;

Tank volume v = 3250 liters

wastewater flows into the tank Q = 200 L/min

TCE concentration Co= 25 mg/L

reactor decays TCE at a reaction rate K = 0.20 min-1

mass balance

we know that;

Accumulation = inflow - outflow ± generation

⇒dc/dt = QCo - Qc ± rc.V

now at a steady state; dc/dt = 0

so

0 = QCo - Qc + rcV

where rc = -kc

0 = QCo - Qc - kcV

Qc + kcV = QCo

c(Q + kV) = QCo  

c = QCo / (Q + kV)

so we substitute

c = (200 × 25) / (200 + (0.2×3250))

c = 5000 / 850

c = 5.88 mg/L      

Therefore,  the steady-state concentration of TCE in the treated water leaving the reactor is 5.88 mg/L  

Can someone help with these questions please???

Answers

1. B
2. A
3. C
4. C

Hope this helps!

Calcium and titanium atoms have the same mass

Answers

Answer:

these elements do not have the same masses.

What are mand n in the rate law equation?
Rate = k[A]”[B]"

Answers

A (they are experimentally determined exponents)

Surface tension is a force that affects....
A. Gases
B. Plasmas
C. Solids
D. Liquids

Answers

Answer:

option A iis the right answer

Surface tension is the tendency of liquid surfaces to shrink into the minimum surface area possible. ... Second is a tangential force parallel to the surface of the liquid. The net effect is the liquid behaves as if its surface were covered with a stretched elastic membrane.

Richard sketched models of two different neutral isotopes of oxygen. If the
isotope models are accurate, which statement might be true? (Refer to the
periodic table if necessary.)
A. One shows 7 protons, and one shows 9.
B. One shows 8 neutrons, and one shows 9.
C. One shows 8 electrons, and one shows 9.
D. One shows 8 protons, and one shows 7.

Answers

Answer:

its b

Explanation:

just did the test on A P E X

If the isotope models are accurate, One shows 8 neutrons, and one shows 9. Therefore, the correct option is option B.

What is isotope?

A chemical element's isotope is one of more than one species of atoms that share the same atomic number, spot on the periodic table, and almost identical chemical activity, but differ in atomic mass and physical characteristics. There are a number of isotopes for each chemical element.

The first step in identifying and labelling an atom is to count the protons within its nucleus. Usually, this nuclear number is denoted by the letter Z. The fact that all atoms possessing the same number of electrons have essentially equal chemical characteristics lends the atomic number its enormous significance. If the isotope models are accurate, One shows 8 neutrons, and one shows 9.

Therefore, the correct option is option B. If the isotope models are accurate, One shows 8 neutrons, and one shows 9.

To know more about isotope, here:

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What is the molarity of a solution made from 325.4g of Aluminum chloride with enough water te
make 500.0 mL?*
(1 Point)
AICIAl = 26.9828 C1 = 35.45
mol
8
mol
0.488M
O 4.88M
0 2.44M
0 2.440M

Answers

Answer:

awdaef

Explanation:

How many formula units of CuCl2 are present in 18.42 g?

Answers

Answer:

Think 12 units

Explanation:

Because it represents the hands of the clock

tell me how is your life as a youngster

Answers

Answer:

ruthless, my style as a juvenile

ran with a gang, slanged in the meanwhile

Explanation:

How many significant figures are in the following measurement? 433.8 liters

Answers

4 significant figures
There are four significant figures in this measurement

list 5 island in the Philippines ​

Answers

Answer:

Coron, Palawan, El Nido, Palawan, Cebu, Boracay, Siargao.

Explanation:

I hope this helps.

coron,palawan,El nidu, Cebu and boracay are 5 island in Philippines.....

3. You can express the density of an object in units of kg/L or in units of
g/mL. How is the density of an object in kg/L related to its density in g/mL?

Answers

They’re equal. There’s 1000 grams in a kilogram and 1000 mL in a liter, so both parts of the fraction change the same and it’s equal

A bullet seized from a crime scene has a composition of lead 11.6 g, tin 0.5 g, and
antimony 0.4 g. What is the percentage of lead in the bullet? Express your answers to
the ones place.

Answers

Answer:

92.8%

Explanation:

Step 1: Given data

Mass of lead in the bullet (mPb): 11.6 gMass of tin in the bullet (mSn): 0.5 gMass of antimony in the bullet (mSb): 0.4 g

Step 2: Calculate the total mass of the bullet

The total mass of the bullet is equal to the sum of the masses of the elements that form it.

m = mPb + mSn + mSb = 11.6 g + 0.5 g + 0.4 g = 12.5 g

Step 3: Calculate the mass percentage of Pb in the bullet

We will use the following expression.

%Pb = mPb / m × 100%

%Pb = 11.6 g / 12.5 g × 100% = 92.8%

CH3CH3C(CH3)2CH2I classification and name​

Answers

Answer:

1,2 di methyl 5 ene tri chloro hexane

5. A reaction in which them material that starts the reaction is also one of the products and can start another reaction is called

a. An accelerator reaction
b. A moderator reaction
c. A shielding reaction
d. A chain reaction

Answers

Answer:

D it's called a chain reaction

How many O atoms are in 7.39 g CO2?

Answers

Answer:

2 O atoms

hope it helps....

Answer:

2O is the correct answer

what process formed slate

Answers

Answer:

Explanation:

Slate is a fine-grained, foliated metamorphic rock that is created by the alteration of shale or mudstone by low-grade regional metamorphism. It is popular for a wide variety of uses such as roofing, flooring, and flagging because of its durability and attractive appearance.

Answer:

Deep within the Earth's crust rocks can be put under huge pressures and temperatures are very high. These conditions can cause the minerals in the rock to change. This process is called metamorphism. Limestone can change into marble, shale and mudstones into slate, and igneous rocks like granite can turn into gneiss.

Explanation:

Slate is a fine-grained, foliated metamorphic rock that is created by the alteration of shale or mudstone by low-grade regional metamorphism. It is popular for a wide variety of uses such as roofing, flooring, and flagging because of its durability and attractive appearance.

1. How would you describe what red cabbage juice is?*
(1 Point)
Acid
Neutral
Alkali
Indicator
Salt​

Answers

Red cabbage juice is a pH indicator.

Iron melts at 1535 °C. What would this temperature be in Fahrenheit

Answers

Answer:

2,795 F

Explanation:

2795 that the answer

What group of elements on the periodic table is not usually found in nature?

Answers

Answer:

Halogens

Explanation:

they they are never found free in nature.

What happens when a base dissolves?
A. It increases the concentration of OH in solution.
B. It increases the concentration of H+ in solution.
C. It adds oxygen to the solution.
D. It is no longer dangerous.

Answers

Answer:

A. It increase the concentration of OH in solutions.

Explanation:

Bases are substances that react with and neutralise acids, producing water. When dissolved, bases release hydroxide ions, OH-(aq) into solution.

When a base dissolves, it increases the concentration of OH⁻ ions in the solution. Therefore, option A is correct.

What are acids and bases?

An acid can be described as a substance that is capable of donating a hydrogen ion to another substance.  A base can be described as a molecule or ion that is able to have a hydrogen ion from an acid.

Acidic materials are commonly identified by sour taste. An acid can be considered commonly a molecule that can donate an H⁺ ion and can be energetically favorable after a loss of H⁺ ion. Acids increase the concentration of H⁺ ions in solution.

Bases are described by a bitter taste and a slippery nature. A base or alkali increases the concentration of OH⁻ ions in the solution. When bases react with acids, they give salts and water as products.

The pH range on the pH scale of the acids lies between 0 to 7 and the pH range of the bases lies between 7 to 14.

Learn more about acids and bases, here:

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Calculate the number of Li atoms in 7.8 mol of Li.

Express your answer using two significant figures.

Answers

Answer:

4.7 × 10²⁴ atoms Li

General Formulas and Concepts:

Math

Pre-Algebra

Order of Operations: BPEMDAS

Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to Right

Chemistry

Atomic Structure

Avogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.

Stoichiometry

Using Dimensional AnalysisExplanation:

Step 1: Define

7.8 mol Li

Step 2: Identify Conversions

Avogadro's Number

Step 3: Convert

Set up:                              [tex]\displaystyle 7.8 \ mol \ Li(\frac{6.022 \cdot 10^{23} \ atoms \ Li}{1 \ mol \ Li})[/tex]Multiply/Divide:                [tex]\displaystyle 4.69716 \cdot 10^{24} \ atoms \ Li[/tex]

Step 4: Check

We are told to round to 2 sig figs. Follow sig fig rules and round.

4.69716 × 10²⁴ atoms Li ≈ 4.7 × 10²⁴ atoms Li

What IONS are present in MgCO₃ (magnesium carbonate)? Mark
all that apply.

A Mg+
B C⁴-
C O2-
D Mg²+
E C⁴+
F CO₃²-

Answers

Answer:

Answer:

Explanation:

"Magnesium is an alkaline earth metal, and forms a Mg2+ ion. And carbonate ion, CO2−3 , has an equal an opposite charge. And thus the ionic species is MgCO3"

Ionic substances are composed of two or more ions. The compound MgCO3 is composed of  Mg²+ and CO₃²- ions.

What are ions?

The term ions refer to charged species that are present in a system. The compound MgCO₃ is an ionic substance and ionic substances are composed of ions.

As such, the compound MgCO₃ is composed of the ions  Mg²+ and CO₃²-.

Learn moer about ions: https://brainly.com/question/365923

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