What is the value for the rate of constant, k(with units)?

Answer: c. Sugar turning black when it burns.

Explanation:

Chemical change is defined as a change in which rearrangement of atoms take place and leads to formation of new substances.  

Physical change is defined as a change which leads to change in shape, size or state of the substance changes. No new substance is formed.

a)  Water bubbling when it starts to boil is a physical change as it accompanies only a change in phase.

b) Detergent removing grease from a dish is a physical change as no new substance is formed.

c) Sugar turning black when it burns is a chemical change as there occurs a chemical reaction between sugar and oxygen. The oxygen in the air reacts with the sugar and the chemical bonds are broken.

d) Oil and vinegar separating in salad  dressing is not a chemical change. It occurs because of difference in densities.

Answer:

balanced forces do not affect the motion of the object.

Explanation:

hhhhhhhhhhhhhhhhhhhhhhhhhhhhhgggggggggggg

Answer:

Explanation:

According to the attached mechanism, we have a Sn1 reaction. The diethyl ether formed is because we have a nucleophilic site and an electrophilic site. Now which one is?.

If you see the mechanism below, you can see that the -OH has a lone pair of electrons. This lone pair attacks the carbon that is attached to the bromine. This attack, makes the ethyl alcohol the nucleophyle, and the ethyl bromide, which have the leaving group (The bromine) the electrophyle.

You can see the mechanism below to understand the formation of this product.

Hope this helps

Explanation:

Molar mass is the the mass of one mole of a substance and is expressed in g/mol. Gold atomic mass is 196.96657, chlorine has 35.453. Hence, molar mass of AuCl3= atomic number of Gold + atomic mass of chlorine × (number of atoms of chlorine in AuCl3). Molar mass of AuCl3 = 196.96657 + (35.453 × 3).

Answer:

increase the number of blocks

increase the number of students pulling the cart

increase the number of blocks and increase the number of students pulling the cart

decrease the number of blocks

decrease the number of students pulling the cart

decrease the number of blocks and decrease the number of students pulling the cart

(ANSWER CHOICES)

Explanation:

Answer:

N2(g) + O2(g) ----->2NO(g)      ΔH= 181 kJ

Explanation:

The equation of the reaction according to the question should be written with the lowest coefficient. A thermochemical reaction usually includes the enthalpy of reaction as part of the reaction equation

So we have the equation of the reaction as;

N2(g) + O2(g) ----->2NO(g)      ΔH= 181 kJ

The positive enthalpy shows that heat was absorbed in the reaction

Answer:

Eric Wu cannot take his pictures on any night because as the Moon orbits the sun different angles of the illuminated half of the Moon is being shown as the days go on. So on some nights the areas of the Moon that Eric Wu wants to take pictures of may not be shown on the Moon because the area is not facing earth.

Explanation:

give me brainly Est

Answer:

goldifsh

Explanation:

Answer: The moles of gas that remain in the cylinder are 0.45

Explanation:

According to the Avogadro's law, the volume of gas is directly proportional to the number of moles of gas at same pressure and temperature. That means,

[tex]V\propto n[/tex]

or [tex]\frac{V_1}{n_1}=\frac{V_2}{n_2}[/tex]

where,

[tex]V_1[/tex] = initial volume of gas = 56.0 L

[tex]V_2[/tex] = final volume of gas = 14.0 L

[tex]n_1[/tex] = initial moles of gas = 1.80  

[tex]n_2[/tex] = final moles of gas = ?

Putting the values , we get:

[tex]\frac{56.0}{1.80}=\frac{14.0}{n_2}[/tex]

[tex]n_2=0.45[/tex]

The moles of gas that remain in the cylinder are 0.45

Explanation:

rubbing it against your hair

Answer:

C

Explanation:

Hope this helps and have a great day.

Answer:

A. Chipping ice to flakes

Explanation:

You can't reverse the ice becoming flakes. They will stay like that until they melt

Answer:

ANSWER: 0.331 moles of tin

Explanation: in my working * means multiply and ^ means to the power of.

Ok BASICALLY if you have 6.02*10^23 of something you have yourself 1 mole of things. The atomic weight in the left hand corner of each element in the periodic table gives you the MOLAR MASS, which is the mass of 1 mole of that element. For example, Carbon has a molar mass of 12.011, this means it has 12.011 grams every 1 mole of carbon [C] (12.011 g/mol)

So now, how many moles are in 39.3 grams of tin? Very easy. You will find that in chemistry classes students are taught a basic formula to find the number of moles, which is:

---

Number of moles = Mass given / Molar mass

---

So in order to answer this question and find out the NUMBER OF MOLES, we need to find the MASS GIVEN - this is simply the mass given to you in the question, which is 39.3 grams of tin. We also need to know the MOLAR MASS, which is found in the left hand corner of the element. For tin [Sn] the molar mass is 118.710.

Sub both these into the formula to get:

Number of moles = 39.3 / 118.710

Number of moles = 0.331058883

We are not finished - remember to round of the lowest amount of significant figures found in the working of the question. In the working out, which was (39.3 / 118.71) the 39.3 has 3 significant figures and the 118.70 has 5 significant figures. ALWAYS TAKE THE LOWEST AMOUNT FOUND. The lowest amount is 3, so we must round this answer to 3 significant figures.

It will be: 0.331

Therefore, 0.331 moles of tin atoms are in a pure tin cup with a mass of 39.3.

Hope i helped and good luck!

Answer:

Since two extra electrons are added, it is denoted by O2- hence it's an ion.

Answer:

See answer below

Explanation:

In order to do this, we need to use the following expression:

N'Au = C'Au * NAu  (1)

Where:

N'Au: number of gold atoms per cubic centimeter.

C'Au = Atomic percentage of the Gold in the gold silver alloy.

NAu = Number of gold atoms

However, we do not have C'Au and neither NAu. We need to calculate those first.

To get the percentage of the gold we use the following expression:

C'Au = (CAu * MMAg) / (CAu * MMAg + CAg * MMAu)   (2)

Where:

CAu and CAg: Weight percentage of the gold and the silve

MMAu and MMag: Atomic weights of the gold and the silver

We already have that data, so, replacing all the given data into (2) we have:

C'Au = (0.10 * 107.87) / (0.10 * 107.87 + 0.90 * 196.97)

C'Au = 10.787 / 188.06

C'Au = 0.0574  (or 5.74%)

We have C'Au, now we need to find the number of atoms of gold in the gold silver alloy. In order to do that, we use the following expression:

NAu = N * ρ / MMAu    (3)

N is the avogadro's number which is 6.02x10²³ atoms. So replacing this value, the density and molecular weight of gold, the atoms are:

NAu = 6.02x10²³ * 19.32 / 196.97

NAu = 5.9x10²² atoms/cm³

Now that we have all the required data from (1), we just need to replace the obtained values:

N'Au = 5.9x10²² * 0.0574

N'Au = 3.39x10²¹ atoms/cm³

Hope this helps

Answer:1. the junk sculpture rules say the forms have to change every two weeks or be taken clear down. 2. the weather and other people change the forms after they are built

Explanation:

Explanation:

1. The junk sculpture rules say the forms have to change every two weeks or be taken clear down.

2.The weather and other people change the forms after they are built.

I hope it's helpful!

Answer:

Ethanol

Explanation:

Solvent extraction is the process in which a compound transfers from one solvent to another owing to the difference in solubility or distribution coefficient between these two solvents(Science Direct).

We have to remember that oxalic acid will be extracted better into a solvent in which it is more soluble. From the data given; oxalic acid is more soluble in ethanol than in ether.

This simply means that ethanol is a better solvent for extracting oxalic acid  from water when compared to ether.

Answer:

15 g

Explanation:

The reaction that takes place is:

First we convert 25 g of KCIO₃ to moles, using its molar mass:

Then we convert KCIO₃ moles to KCl moles, using the stoichiometric coefficients:

Finally we convert KCl moles to grams, using the molar mass of KCl:

Answer:

D: A white blood cell produces antibodies.

Explanation:

Intercellular communication is defined as the process of communication that occurs between the two cells of the same organism.

Now, these two cells relate which each other when a signal reception receives a single molecule at a distance that could be short or long which in turn produces a cellular response.

Thus, looking at the options, the correct answer is Option D.

Answer:

1.47

Explanation:

1) Avogadro number is: 6.022*10²³ molecules per mol;

2) if 6.022*10²³ molecules are in 1 mol, then 4.11*10²³ molecules are in

x=6.022*10²³ / 4.11*10²³=6.022/4.11≈1.47 moles.

Answer:He2 & O2

Explanation:

Answer:

Answer:A

Explanation:

Answer:

52.9031 hope this helps:)

Explanation:

Answer:

Confederation
☆

EDGE2022; Good Luck :3!!!!

2 H2O2 - 2 H2O+O2 - Balanced Equation and its a decomposition reaction.

Answer:

See explanation and image attached

Explanation:

Esterification is a reaction of an alkanol and an alkanoic acid to yield an ester and water as products. It is analogous to inorganic neutralization reaction.

The process may be acid catalyzed. As mentioned in the question, the process of ester formation between pentanoic acid and n‑propanol first involves the carbonyl in going through an sp3 hybridized intermediate before returning to sp2 hybridized state in the product.

The image of the neutral form of this intermediate as well as the final structure of the ester are both shown in the image attached to this answer.

Answer:

distance and time

Explanation:

distance=rate x time

rate=speed

Answer:

Kauai

Explanation:

I look this up when I am doing math

Answer:

The answer is the skin of the apple

Answer:

2.50x10²¹ atoms

Explanation:

First we convert the given mass of dimercaprol to moles, to do so we calculate its molar mass:

515 mg equal 0.515 g

As one dimercaprol molecule binds to one As atom, one mol of dimercaprol reacts with one mol of As.

So we convert those 4.146 x 10⁻³ mol of As to atoms, using Avogadro's number: