During an exothermic reaction, H for the reactants was 890 kJ/mol. Which of the following statements is correct about the H for the products and the comparison of the energy in bonds? (5 points) Select one: a. It is less than 890 kJ/mol, and the amount of energy required to break bonds is greater than the amount of energy released in forming bonds. b. It is less than 890 kJ/mol, and the amount of energy required to break bonds is less than the amount of energy released in forming bonds. c. It is greater than 890 kJ/mol, and the amount of energy required to break bonds is greater than the amount of energy released in forming bonds. d. It is greater than 890 kJ/mol, and the amount of energy required to break bonds is less than the amount of energy released in forming bonds.

Answer:

Fossil energy has been a fundamental driver of the technological, social, economic and development progress which has followed.In 2019, around 84% of global primary energy came from coal, oil and gas. Over the coming decades we need to rapidly reduce this share by displacing them with low-carbon energy sources.Fossil energy has been a fundamental driver of the technological, social, economic and development progress which has followed.In the sections above we looked at the consumption of fossil fuels collectively. But it’s important to look at the role of coal, oil and gas individually – their impacts are not equal. Coal, for example, typically produces more CO2 and local air pollution per unit of energy.There would be more research on the use of alternate fuels.Moreover, fossil fuels are composed primarily of carbon and hydrogen atoms. On combustion they produce carbon dioxide, sulfur dioxide, and carbon monoxide as the main by-products.Solar energy can only be captured during daylight hours.

Explanation:

if you write this then you will get full marks in your assignment it is valied for up to 16 class I don't know about any further it I have mixed many iconic and logic facts that are imp in science!

Answer:

ethyl methyl ether

Explanation:

when naming ethers name the alkyl rings, in this case we have methyl and ethyl( make sure they are in alphabetical order) followed by the word ether, so it becomes ethyl methyl ether

Answer:

4

Explanation:

C4H8

Answer:

See Explanation

Explanation:

Ionic compounds are composed of crystals. The crystal structure of an ionic compound is responsible for its hardness.

A crystalline solid contains a well organized structure which enables it to be hard and have a particular geometric shape as well defined melting point.

Hence, all the observed characteristics of NaCl are the result of its crystalline structure.

Answer:

If you wash your hands with soap, the soap molecules act as a link between the water you're washing with and the oil on your skin.

Explanation:

Answer:

I doint understand that question resend it again

[tex]V_{1} = \text{5 L}[/tex]

[tex]T_{1} = \text{298 K}[/tex]

[tex]V_{2} = \text{3 L}[/tex]

[tex]T_{2}[/tex]

[tex]\dfrac{V_{1}}{T_{1}} = \dfrac{V_{2}}{T_{2}}[/tex]

[tex]T_{2} = T_{1} \times \dfrac{V_{2}}{V_{1}}[/tex]

[tex]T_{2} = \text{298 K} \times \dfrac{\text{3 L}}{\text{5 L}}[/tex]

[tex]\boxed{T_{2} = \text{179 K}}[/tex]

[tex]\\[/tex]

#ChemistryIsLife

#ILoveYouShaina

Answer:

D

Explanation:

because moles = mass /mr

so 81/18(mr of H2O=2+16)

moles =4.5

hope this helps:)

Answer:

True

Explanation:

Answer:

1..CO3

2..OH

3..CO

4..Cl

5..PO3

6..SO4

8..NO3

9..NO2

1O..I2

A molecular formula consists of the chemical symbols for the constituent elements followed by numeric subscripts describing the number of atoms of each element present in the molecule. The molecular formula for a compound can be the same as or a multiple of the compound's empirical formula.

I hope it seemed helpful to you!

Answer:

Molecular formulas describe the exact number and type of atoms in a single molecule of a compound. The constituent elements are represented by their chemical symbols, and the number of atoms of each element present in each molecule is shown as a subscript following that element’s symbol. The molecular formula expresses information about the proportions of atoms that constitute a particular chemical compound, using a single line of chemical element symbols and numbers. Sometimes it also includes other symbols, such as parentheses, dashes, brackets, and plus (+) and minus (–) signs.

Answer:

Salt

Explanation:

It is because it has a defined composition.

Answer:

Salt

Explanation:

Pure substances are those that contain atoms or molecules of the same type. For eg: elements are pure (gold, hydrogen etcl.) and compounds (such as water, sodium chloride, etc.), etc.

Rest of choice are impure because they contain a mixture of different things, like pie has eggs, or all sorts of other molecules, salt water has water and salt molecules, and iced tea has water and other molecules associated with tea.

Answer:

d

Explanation:

As + O2 -------->as2o3

Explanation:

i colour code it so hopefully it make sense:)

Explanation:

The molecules move more slowly and their average kinetic energy decreases

The molecules move more slowly and their average kinetic energy decreases. Hence, option B is correct.

On the molecular level, the individual chemical bonds in the substance are not altered; hence, a phase change is not a chemical reaction.

At the molecular level, the temperature is related to the random motions of the particles (atoms and molecules) in matter.

Because there are different types of motion, the particles' kinetic energy (energy of motion) can take different forms, and each form contributes to the total kinetic energy of the particles.

Hence, option B is correct.

Learn more about the molecular level here:

https://brainly.com/question/2449642

#SPJ2

Answer:

240 N/m

Explanation:

Using the formula as follows:

U = ½kx²

Where;

U = elastic potential energy (J)

K = spring constant (N/m)

x = stretched displacement (m)

According to the information provided in this question,

U = 35J

x = 0.54m

k = ?

U = ½kx²

35 = ½ × k × 0.54²

35 = ½ × k × 0.2916

35 = 0.2916k/2

70 = 0.2916k

k = 70 ÷ 0.2916

k = 240.05

To 2s.f, the spring constant (k) = 240 N/m.

Answer: 240

Explanation:

Answer:

C

Explanation:

because it is complete combustion so it will produced CO2 +H2O :)

Answer:

%K=38,6%  %N=13,86%   %O=47,54%

Explanation:

%K=M K/M KNO3

  =39/101

=38,6%

%N=14/101

=13.86%

%O=100%-%K-%N

=100-38,6-13,86

=47,54%

Answer:

true

Explanation:

Answer:

See explanation

Explanation:

Qualitative analysis in chemistry is a method used to determine the ions present in a solution chiefly by means of chemical reactions.

In this case, I suspect the presence of silver ions and/or barium ions. The first step is to add dilute HCl. This will lead to the precipitation of the silver ion as AgCl. If a white precipitate is formed upon addition of HCl then Ag^+ is present in the solution.

Secondly, I add a carbonate such as NH4CO3(aq). This will cause the barium ions to become precipitated as barium carbonate. Hence, the formation of a white precipitate when NH4CO3(aq) is added to the solution indicates the presence of barium ion in the solution.

Answer: SMALLEST is lithium

LARGEST is Fluorine

Explanation:

Answer:

Công thức muối sắt là FeCl_3 nha bạn.

Answer:

B. 87%

Explanation:

First, we calculate the molecular mass of magnesium bromide (MgBr2) as follows;

MgBr2 = 24.3 + 79.9(2)

= 184.1g/mol

Since 1 atom of bromine contains 79.9g, then the mass of two atoms of bromine (Br2) is 79.9 × 2 = 159.8g

Hence, the percentage of bromine (Br2) in MgBr2 is calculated as follows:

% mass of Br2 = mass of Br2/ molecular mass of MgBr2 × 100

% mass of bromine = 159.8/184.1 × 100

% mass of bromine = 0.8680 × 100

% mass of bromine = 86.8%

Approximately, % mass of bromine is 87%

Answer:

Global Warming , Volcanic Eruption

Answer:

H

Explanation:

not sure tho sorry if I'm wrong