When the surface of a mirror curves inward, like the inside of a bowl, it is called a ___

ruslelena [56]

Answer:

a. ionic, 211.62g/mol

b. molecular, 149g/mol

c. molecular, 342g/mol

Explanation:

Ionic Compound: These are compounds (2 or more elements) where atoms of the element have lost or gained electrons, thus they are ions, thus the name ionic. An easy way to identify ionic compounds is to see if there are any metals. Metals tend to give up their electron to a non-metal. It maybe helpful to familiarize which parts of the periodic table have metals and non-metals.

Molecular Compounds: These are compounds (2 or more elements) that are neutral. An easy way to identify them is that the compound is made up of just non-metals.

Molar Mass is the masses of each individual element in the compound. Refer to the periodic table for the masses and add them up carefully, remember to multiply their mass based on how many molecules there are in the compound, like for a, we can find the mass of NO3, but we need to multiply it by 2 since we have 2 molecules of NO3.

a. Sr(NO3)2

Sr= 87.62

NO3= 14 + (3 x 16)= 62

Sr + 2 (NO3)

87.62 + (2 x 62)= 211.6

b. (NH4)3PO4

NH4= 14 + 4 = 18

PO4= 30.97 + (4 x 16)= 94.9

(NH4 x 3) + PO4

(18 x 3) + 94.9 = 149

c. C12H22O11

(12 x C) + (22 x H) + (11 x O)

(12 x 12) + (22 x 1) + (11 x 16)

144 + 22 + 176= 342

4 0

3 years ago

Heating up a reaction does which of the following:

Svetradugi [14.3K]

Heating up a reaction does increase the number of collision only.

Hence, Option C is correct answer.

<h3>What is Collision Theory ? </h3>

According to the collision theory, the reaction take place when the collision occur and molecules having sufficient energy or threshold energy for collision.

The collision of molecules depend on the kinetic energy of molecules. Greater the kinetic energy greater the number of molecules collide. Lesser the kinetic energy lesser will be collision.

<h3>How temperature affect the collision theory ?</h3>

With an increase in temperature, there is an increase in energy that can be converted into activation energy in a collision, and that will increase the reaction rate. A decrease in temperature would have the opposite effect. With an increase in temperature, there is an increase in the number of collision.

Thus from the above conclusion we can say that Heating up a reaction does increase the number of collision only.

Hence, Option C is correct answer.

Learn more about collision theory here:

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7 0

1 year ago

nuclear decay occurs according to first-order kinetics. a nuclide decays in 3.40 days from 45.0 g to 12.1 g. what is the rate co

Ad libitum [116K]

The rate constant for the nuclide according to first-order kinetics is 0.3863 per day.

Nuclear Decay in First-Order Kinetics:

m(t) = Me∧(-αt)

where m(t) = mass of nuclide after decay at time t;

M = mass of nuclide before decay;

α = rate constant of decay;

t = time for the decay;

<h3>What is first-order kinetics?</h3>

When a fixed percentage of the drug is excreted per unit of time, this is known as first-order kinetics.

For example, The amount of drug in the body has a direct relationship to the rate of removal. The amount of medication eliminated per unit of time increases with concentration. The medication concentration decreases by 50% for each half-life.

Now,

m(t) = Me∧(-αt)

⇒e∧(αt) = M/m(t)

applying ln on both sides;

αt = ln(m/m(t))

α = (ln(m/m(t))/t)

here t= 3.4 days, M = 45 grams, m(t) = 12.1 grams;

dropping these values in the above equation we get,

α = 0.3863 per day;

The rate constant for the nuclide according to first-order kinetics is 0.3863 per day.

To refer more about First Order Kinetics visit:

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4 0

1 year ago

Which of the following is an oxidation-reduction reaction? Which of the following is an oxidation-reduction reaction? Ba(C2H3O2)

DochEvi [55]

Answer:

The only oxidation- reduction reaction is <u>Cu (s) + 2AgNO3 (aq) → 2Ag (s) + Cu(NO3)2</u>

Explanation:

An oxidation-reduction reaction is a chemical reaction that involves an electron transfer between two species. This will lead to a change in oxidation number of a molecule, atom, or ion changes by gaining or losing an electron.

Some atoms have different possible oxidation numbers.

H has oxidation number +1

O has oxidation number -2

The oxidation number of an individual atom is 0.

The total oxidation number of all atoms in: a neutral species is 0 and in an ion is equal to the ion charge.

⇒ Ba(C2H3O2)2 (aq) + Na2SO4 (aq) → BaSO4 (s) + 2NaC2H3O2

(C2H3O2)2 has an oxidation number of -2. So Ba has an oxidation number of +2

In BaSO4 has SO4 an oxidation number of -2 and Ba has an oxidation number of +2

This means <u>Ba doesn't change its oxidation number.</u>

In Na2SO4 Na has an oxidation of +1; in NaC2H3O2 Na has an oxidation of +1

This means <u>Na doesn't change its oxidation number. </u>

<u />

Cu has an oxidation number of 0

In Cu(NO3)2, NO3 has an oxidation number of -1 so Cu has an oxidation number of +2

In 2AgNO3, NO3 has an oxidation number of -1 so Ag has an oxidation number of +1

Ag has an oxidation number of 0

⇒ HCl (aq) + NaOH (aq) → H2O (l) + NaCl

The oxidation number of Cl and Na do not change

⇒ AgNO3 (aq) + HCl (aq) → AgCl (s) + HNO3

In AgNO3 Ag has an oxidation number of +1

In AgCl Ag has an oxidation number of +1

In HCl Cl has an oxidation number of -1

In AgCl Cl has an oxidation number of +1

The oxidation number of Cl and Ag do not change

⇒ H2CO3 (aq) + Ca(NO3)2 (aq) → 2HNO3 (aq) + CaCO3 (s)

In Ca(NO3)2 Ca has an oxidation number of +2

In CaCO3 Ca has an oxidation number of +2

In Ca(NO3)2 N has an oxidation number of +5

In HNO3 N has an oxidation number of +5

In H2CO3 C has an oxidation number of +4

In CaCO3 C has an oxidation number of +4

The only oxidation- reduction reaction is <u>Cu (s) + 2AgNO3 (aq) → 2Ag (s) + Cu(NO3)2</u>

<u />

Oxidizing agent: Ag ; Reducing agent: Cu

4 0

3 years ago

Can someone help me I need help please!

zavuch27 [327]

Answer:

Explanation:

the number above the letter is the atomic number and the other on the bottom is the atomic mass . and the mass number is the atomic mass . and protons is the number above the letter along with neutrons electrons you just do atomic mass - atomic number = electrons

example 1 -2= 1 so there is the atomic number of 1 and atomic mass of 2

let me know if this helps

6 0

3 years ago

When the surface of a mirror curves inward, like the inside of a bowl, it is called a ____.