Which of the following is an example of a combustion reaction?
A) Mixing of an acid and base
B) Photosynthesis in plants
C) Lighting of a Matchstick
D) Reacting sodium and chlorine

Answer:

Im a 100% sure it is B. average molecular speed of ethane is greater than the average molecular speed of propanol.

Explanation:

Sry I didnt' get the explaination from my teacher.

According to the Kinetic theory of gases, the average speed of all gases at the same temperature will be in the same range. Hence, option C is correct.

Kinetic theory of gases states the properties and composition of gases at a temperature and pressure. According to this theory, gaseous substances are made of tiny particles which are free to move and collide to each other.

The kinetic energy of the particles is directly proportional to the temperature. Hence, as the temperature increases, the kinetic energy increases and their average molecular speed increases.

At the same temperature, all the gases have equal range of average molecular speed irrespective of their molecular weight. Hence, at 400 K the average molecular speed of ethane and propanol will be the same.

Find more on kinetic theory :

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Answer:

Explanation:

Start with the number of grams of each element, given in the problem.

Convert the mass of each element to moles using the molar mass from the periodic table.

Divide each mole value by the smallest number of moles calculated.

Round to the nearest whole number. This is the mole ratio of the elements and is.

Answer:

Below are some patterns in the charge for elements in each group.

Group 1 elements : 1 valence electron and form ions with charge +1

Group 2 elements : 2 valence electrons and form ions with charge + 2

Group 3 elements : 3 valence electrons and form ions with charge + 3(there are some exceptions as well)

Elements in groups 4 and 5 are unpredictable also the D block elements consist of multiple oxidation states..

Group 6 elements : 6 valence electrons, form ions with charge -2

Group 7 elements: 7 valence electrons, form ions with charge -1  

The octet rule is being followed, the elements form either ionic bond or covalent bond to fulfill it.

eg: when a K atom forms a K+ ion, the ion has the same electron configuration as the noble gas Ar (argon).

When an O atom gains 2 electrons to form the O²⁻ ion, the ion has the same electron configuration as the noble gas Ne (neon).  

Note: Boron (B) is in Group 3 but doesn't form ions.

A noticeable pattern in the charge for elements in each group of the periodic table is that: Elements in the same group have the same charge.

Discussion:

The pattern in the charge for elements in each group is characterized by the adoption of the same charge for elements in the same group irrespective of the period they are situated in.

An example is evident in the alkali metal, halogen and alkali Earth metals group.

The alkali metals lose their only Valence electron, to assume the octet configuration of the preceeding noble gas.

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Answer:

Wave

Explanation:

/~\ The correct answer is:

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Hydrogen is a chemical and is found in the sun and most of the stars, and the planet Jupiter is composed mostly of hydrogen. On Earth, hydrogen is found in the greatest quantities as water.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

I hope this helps! /~\

Answer:

hydrochloride acid

Explanation:

hope this helps :D

Answer:

10 kg of ice will require more energy than the released when 1 kg of water is frozen because the heat of phase transition increases as the mass increases.

Explanation:

Hello!

In this case, since the melting phase transition occurs when the solid goes to liquid and the freezing one when the liquid goes to solid, we can infer that melting is a process which requires energy to separate the molecules and freezing is a process that releases energy to gather the molecules.

Moreover, since the required energy to melt 1 g of ice is 334 J and the released energy when 1 g of water is frozen to ice is the same 334 J, if we want to melt 10 kg of ice, a higher amount of energy well be required in comparison to the released energy when 1 kg of water freezes, which is about 334000 J for the melting of those 10 kg of ice and only 334 J for the freezing of that 1 kg of water.

Best regards!

Answer:

3.077 × 10¹⁴ Hz

Explanation:

f = ?

wavelength = 9.75 × 10-⁷m

using the formula,

c = wavelength × frequency

f = c/wavelength

but c(speed of light) = 3×10⁸m/s

f = 3 × 10⁸/9.75 × 10-⁷

f = 3.077 × 10¹⁴ s-¹

* Lab question: How can you distinguish a physical change from a chemical change?

> Format: How can you distinguish A from B?

Answer! Comparison: physical changes vs. chemical changes

Volume of Ba(OH)₂ : 0.363 L

Balanced equation :

H₂(g)+S(s)+2OH⁻(aq)⇒ S²⁻(aq)+2H₂O(l) (eq 1)

Ba(OH)₂⇒Ba²⁺+2OH⁻ (eq 2)

mol S :

[tex]\tt \dfrac{3~g}{32~g/mol}=0.09375[/tex]

mol OH from eq 1 : (mol S : mol OH = 1 : 2)

[tex]\tt \dfrac{2}{1}\times 0.09375=0.1875[/tex]

mol Ba(OH)₂ from eq 2 : (mol Ba(OH)₂ : mol OH⁻=1 : 2)

[tex]\tt \dfrac{1}{2}\times 0.1875=0.09375[/tex]

volume of Ba(OH)₂ :

[tex]\tt Volume =\dfrac{mol}{M}=\dfrac{0.09375}{0.258}=0.363 L[/tex]

Answer: i think it is A

Explanation:

hope this helps!

Answer:

Yes

Explanation:

It is heating up both

Answer:

c elevation

Explanation:

C is the answer for your question

Answer:

x and y

Explanation:

Answer:

wx

Explanation:

Because the w is going toward the x

Question: ¿What is molar mass of C7H6O2?

Answer: 122,12 g/mol

IamSugarBee

Answer:

the answer in simplest form is A) N2H

Answer:

Frame of Reference

The fixed background surrounding an object, assumed to be at rest and in a fixed position.

Answer:

Porque las moléculas de glucosa son salvajes

Explanation:

Answer:

Glucose cannot move across a cell membrane via simple diffusion because it is simple large and is directly rejected by the hydrophobic tails. Instead it passes across via facilitated diffusion which involves molecules moving through the membrane by passing through channel proteins.

Explanation:

The phrase that most accurately describes a chemical change is; "A change on the molecular level."

The major difference between a physical change and a chemical change is that a chemical change involves a change in the composition of a substance.

This implies that the atoms in a substance are rearranged during a chemical change.

This rearrangement of atoms corresponds to change on a molecular level.

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Answer:What volume of 9.00 M nitric acid is needed to make 6.50 L of 1.25 M solution? 903 mL What molarity should the stock solution be if you want to dilute 25.0 mL to 2.00 L and have the final concentration be 0.103 M?

Explanation:

The question is incomplete, the complete question is;

Chris the Chemist was working in the lab, and he wanted to see what would happen if he put copper chloride into a Bunsen burner flame. As soon as he put it in the flame, it began to emit a green color. Which of these BEST describes this outcome?

A) The heat split the nucleus and created a new element.

B) As the copper chloride was heated, electrons were turned into neutrons.

C) As the electrons moved to a higher energy level, a photon of light is emitted.

D) When excited electrons return back to the ground state, a photon of light is emitted.

Answer:

D) When excited electrons return back to the ground state, a photon of light is emitted.

Explanation:

According to Bohr's model of the atom, electrons may absorb energy and move up to higher energy levels.

These electrons quickly return to ground state from such higher energy excited states thereby emitting the excess energy absorbed during excitation.

If the higher energy level is E2 and the ground state is E1 then the energy of the photon emitted when the electron descends from energy level E2 to E1 is;

ΔE = E2 - E1

This photon emitted accounts for the green colour of the copper salt observed when it was heated.

Answer:

It would be C because its continuing to the next. It doesn't stop nor does it absorb anything.

Explanation: I hope this helps :) I'm only in 8th grade but this seems easy so if I am wrong I am soo sorry.

Answer:

It occurs when a gas passes through a tiny hole.

Explanation:

Effusion is a term used to describe when a gaseous molecule in a container passes or escapes through a tiny/small hole. Effusion and diffusion are two properties of gases that are often used interchangeably, however, they differ.

Effusion differs from diffusion in the sense that the gas passes through a TINY HOLE that is smaller than the normal path. This is contrary to when gas disperses throughout a container as in diffusion.

The correct answer is:

A) It occurs when a gas passes through a tiny hole.

Answer:

.......................................................

Explanation:

Answer:

1.1 mol H₂O

General Formulas and Concepts:

Chemistry

Explanation:

Step 1: Define

6.8 × 10²³ molecules H₂O

Step 2: Convert

[tex]6.8 \cdot 10^{23} \ mc \ H_2O(\frac{1 \ mol \ H_2O}{6.022 \cdot 10^{23} \ mc \ H_2O} )[/tex] = 1.12919 mol H₂O

Step 3: Check

We are given 2 sig figs. Follow sig fig rules.

1.12919 mol H₂O ≈ 1.1 mol H₂O

Answer:

Our final conversion is 1.1 moles of water.

Explanation:

When we want to find the amount of moles in a substance, we can use dimensional analysis or conversion factors in order to convert it from molecules, grams, atoms, formula units, or virtually any other unit.

We are given that we want to convert 6.8 x 10²³ molecules of water to moles. We can set up a dimensional analysis table to solve this.

In dimensional analysis, we multiply across the top and then divide the results by the multiplied value on the bottom.

[tex]\begin{tabular}{c|c}6.8 \times 10^{23} \ \text{molec. of water} & \text{1 mol H}_2 \text{O} \\ \cline{1-2} 1 & 6.022 \times 10^{23} \ \text{molec. of water} & \end{tabular}[/tex]

Now, we will perform our calculations and find our final answer.

[tex](6.8 \times 10^{23}) \times (1) = 6.8 \times 10^{23}[/tex]

[tex](1) \times (6.022 \times 10^{23}) = 6.022 \times 10^{23}[/tex]

[tex]\huge\frac{6.8 \times 10^{23}}{6.022 \times 10^{23}} = 1.129192959[/tex]

[tex]\text{Round to significant figures} \rightarrow 1.129192959 \approx 1.1[/tex]

Therefore, using our table, we have determined that our final answer is 1.1 moles of water.

[tex]\begin{tabular}{c|c}6.8 \times 10^{23} \ \text{molec. of water} & \text{1 mol H}_2 \text{O} \\ \cline{1-2} 1 & 6.022 \times 10^{23} \ \text{molec. of water} & \end{tabular} = 1.1 \text{moles of water}[/tex]

Answer:

B. water displacement is used "graduated cylinder is filled with water (100 mL) and the object is then put inside. ... If the new water level is (120 mL) we now know that the object has a volume of 20 mL."

Explanation:

Answer:

I think it would be b.water displacement

Answer:

Cobalt (III) Iodide

General Formulas and Concepts:

Chemistry - Compounds

Explanation:

Step 1: Define

CoI₃

Step 2: Identify

Co is a Transition Metal, has either a charge of 2+ or 3+

I is a Halogen, has a charge of 1-

Step 3: Write name

We need to balance the charges, and in order to do that, we must have a Co³⁺

Cobalt (III) Iodide

Answer:

0.282 M

General Formulas and Concepts:

Chemistry - Solutions

Explanation:

Step 1: Define

5.85 g KI

0.125 L

Step 2: Identify Conversions

Molar Mass of K - 39.10 g/mol

Molar Mass of I - 126.90 g/mol

Molar Mass of KI - 39.10 + 126.90 = 166 g/mol

Step 3: Convert

[tex]5.85 \ g \ KI(\frac{1 \ mol \ KI}{166 \ g \ KI} )[/tex] = 0.035241 mol KI

Step 4: Find Molarity

M = 0.035241 mol KI / 0.125 L

M = 0.281928

Step 5: Check

We are given 3 sig figs. Follow sig fig rules and round.

0.281928 M ≈ 0.282 M