a. silicon
b. carbon
c. beryllium
d.chromium

Answer:

You can look at the charge of the molecule.

mg has a +1 charge so the oxidation numbrr for Mg = +1.

For Fe2O3 the total charge is 0. This means the charges of the Fe and the O needs to be equal. O has an oxidation number of -2. You got O3 so 3 x -2 = -6. You got Fe2 so -6 / 2 = -3. Oxidation number of O = -2 and for Fe = -3.

The if you go to the rightbof the reaction you got 3 MgO. O had an oxidation number of -2. The total charge of the molecule is 0 zero, so Mg should be +2.

Mg on the left of the equation has a oxidation number of +1, and on the right +2. The number changed, so it's a redox reaction.

Answer:

204.5505 grams

2.5666 moles

Explanation:

For the first question, multiply 3.5 (# of moles) by 58.443 (g/mol for NaCl).

58.443 * 3.5

I'll distribute 3.5 into 58.443.

(3.5 * 50) + (3.5 * 8) + (3.5 * 0.4) + (3.5 * 0.04) + (3.5 * 0.003)

175 + 28 + 1.4 + 0.14 + 0.0105

203 + 1.4 + 0.14 + 0.0105

204.4 + 0.14 + 0.0105

204.54 + 0.0105

204.5505 grams

There are 204.5505 grams in 3.5 moles of NaCl.

For the second question, divide 150 (# of grams) by 58.443 (g/mol for NaCl). I'll convert both into fractions.

150/1 * 1000/58443

150000/58443

2.56660336 moles

2.5666 moles (rounded to 4 places to keep consistency with the first answer) are in 150 grams of NaCl.

Answer:

218.98 grams

Explanation:

Given that,

No. of moles, n = 2.3

The molar mass of magnesium chloride is 95.211 g/mol.

We need to find the mass of 2.3 moles of magnesium chloride.

We know that,

No. of moles = given mass/molar mass

Let m be the given mass. So,

[tex]m=n\times M\\\\=2.3\times 95.211 \\\\=218.98\ g[/tex]

So, the required mass is equal to 218.98 grams.

Answer:

Charges that are opposite each other, such as positive and negative charges, draw each other. Like charges repel each other, such as two negative charges or two positive charges.

Explanation:

Answer:

Opposite electric forces attract each other.

Like if it's positive and negative they will come together.

If they are the same(positive and positive or negative and negative) they will repel each other.

Explanation:

Answer:

To prevent the mixture from separating substances called emulsifiers can be added. These help to form and stabilise the emulsions, preventing or slowing the water and fat/oil from separating. ... The hydrophilic end of the emulsifier molecule is attracted to the water and the hydrophobic end is attracted to the fat/oil.

Answer:

Yes

Explanation:

3NaOH + H3PO4

3Na + 3O + 3H + 3H + P + 4O

3Na + 7O + 6H + P

Na3PO4 + 3H2O

3Na + P + 4O + 6H + 3O

3Na + 7O + 6H + P

Answer:

answer is will be C) ok alright

Answer:

Rate = K[NH4+][NO2–]

Explanation:

Hello there!

In this case, since rate laws include the concentration of the species contributing to the rate of a chemical reaction; this question asserts this reaction is proportional to the concentration of ammonium (NH4+) and the concentration of nitrogen dioxide (NO2–); therefore, the rate law must contain the concentration of both reactants, for that reason, the answer would be Rate = K[NH4+][NO2–] as it contains the concentration of the aforementioned species.

Regards!

Answer: Diploid Cells (?)

Explanation:

Answer:

Barium.

Explanation:

Each chemical element is characterized by the number of protons in its nucleus, which is called the atomic number Z. But in the nucleus of each element it is also possible to find neutrons, whose number can vary. The atomic mass (A) is obtained by adding the number of protons and neutrons in a given nucleus.

The same chemical element can be made up of different atoms, that is, their atomic numbers are the same, but the number of neutrons is different. These atoms are called isotopes of the element. Isotopes means "same place", that is, since all the isotopes of an element have the same atomic number, they occupy the same place in the Periodic Table. So if a neutron is added to an atom, it becomes an isotope of that chemical element.

The isotopes of an element have the same chemical properties, but differ somewhat in their physical properties.

Barium has an atomic number of 56 (number of protons). Also, the mass number of this barium isotope is 130 (56 protons + 76 neutrons). Finally, since it has 54 electrons, two negatively charged electrons less than the number of positively charged protons, this isotope is a cation with oxidation number +2.

Answer:

Freezing point of water will decrease to -18.02°C

Explanation:

We start from the formula for freezing point depression, one of the colligative properties.

ΔT = Kf . m . i

ΔT = Freezing T° of pure solvent - Freezing T° of solution

m = molality

Kf = Cyoscopic constant (specific for each solvent)

i = numbers of ions dissolved (Van't Hoff factor)

CaCl₂ →  Ca²⁺  + 2Cl⁻    i = 3

We replace each data:

0°C - T° F) = 1.86°C/m . 3.23 m . 3

T°F = - 18.02°C

Answer: Exothermic because the ΔH is negative.

Explanation:

The standard enthalpy of formation or standard heat of formation of a compound is the change of enthalpy during the formation of 1 mole of the substance from its constituent elements, with all substances in their standard states.

[tex]C(s)+O_2(g)\rightarrow CO_2(g)[/tex]

Exothermic reactions are those reactions in which heat is released and [tex]\Delta H[/tex] is negative.Endothermic reactions are those reactions in which heat is absorbed and [tex]\Delta H[/tex] is positive.

The reaction is exothermic as the heat is released during the formation of [tex]CO_2[/tex] as heat of formation of [tex]CO_2[/tex] is negative.

Answer:

In a bottle.

Explanation:

I would like soda in a bottle because you don't get soda stuck in the aluminum can like you do a bottle. And it's also way more efficient because bottles have caps that you can screw on later, but aluminum doesn't.

Answer:

Valence electrons occupy the outermost shell or highest energy level of an atom while core electrons are those occupying the innermost shell or lowest energy levels. This difference greatly influences the role of the two types of electrons in a chemical reaction.

Answer:

A) day and night

Explanation:

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Answer:

You answer is A

Explanation:

Without the earth rotating on its axis, we wouldn't have day or night because we will be stuck facing the sun or the moon forever.

Answer: true

Explanation:

true

can you explain it further

The Fe is our limiting reactant here. First, convert the mass of Fe given to moles of Fe by dividing mass by the molar mass:

(51.3 g Fe)/(55.845 g/mol) = 0.9186 mol Fe.

According to the balanced equation, 2 moles of Fe2O3 are produced for every 4 moles of Fe that are consumed. In other words, half as many moles of Fe2O3 will be produced as there are Fe that react:

(0.9186 mol Fe)(2 mol Fe2O3/4 mol Fe) = 0.4593 mol Fe2O3.

Finally, convert the moles of Fe2O3 back to grams by multiplying by the molar mass of Fe2O3:

(0.4593 mol Fe2O3)(159.6882 g/mol) = 73.3 g Fe2O3.

So, 73.3 grams of Fe2O3 are formed.

Answer: c= 1.8 mol/l

Explanation: amount of substance remains same.

Amount of substance n = c1·V1 = c2·V2 and c1= c2·V2/ V1

Original concentration c1= 300 ml·0.750 mol/l / 125 ml

Answer:

The molar mass of the gas is 90.4g/mol

Explanation:

To solve this question we have to use the equation:

d = PM / RT

Where d is density of the gas = 2.29g/L

P is pressure = 0.75atm

M is molar mass of the gas = ??

R is gas constant = 0.082atmL/molK

T is absolute temperature = 88°C + 273.15 = 361.15K

Solving for M:

dRT / P = M

2.29L*0.082atmL/molK*361.15K / 0.75atm = M

90.4g/mol = M

The molar mass of the gas is 90.4g/mol

Answer:

Mountain ranges and prevailing winds.

Explanation:

Mountain ranges and prevailing winds are the factors that is responsible for the difference in the precipitation between Nevada and Washington states. The Washington state is located along the coastal region of pacific ocean and having more mountain ranges which causes more rainfall in that region while on the other hand, Nevada state comprise of plateau, basins and far away from the ocean which is the main cause of lower rainfall as compared to Washington state.

Answer:

Endothermic and Exothermic Reactions

Endothermic and Exothermic ReactionsIn this experiment you are investigating whether dissolving ammonium nitrate in water is an endothermic or exothermic reaction. An endothermic reaction absorbs energy from its surroundings (heat), so the reaction gets colder.

Explanation:

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Answer: the compound used in disinfecting water is called Bleaching powder. It's chemical formula is CaOCl2 ( calcium oxychloride).

Explanation:

Water is a universal solvent. It is polar in nature and dissolves most inorganic solutes and some polar organic solutes to form aqueous solutions. Rain, springs, well, rivers, lakes and sea are natural sources of water.

Most natural water contains dissolved mineral salts, suspended impurities and germs. Therefore to make it safe for domestic and industrial use, water from natural resources undergoes in water treatment tanks:

--> coagulation,

--> sedimentation,

--> filtration and

--> disinfection.

Taking a quick glance at the whole process z water is first collected in large tanks and filtered to remove large particles. Chemical like CA(OH)2 is added to coagulate the fine particles. The coagulated particles are removed by using filter beds. Then the Bleaching powder (calcium oxychloride) is added to kill the bacteria ( disinfection). Then water is ready for use.

Answer:

You need a balanced equation.

2Fe(s) + 3S(s) ==> Fe2S3(s) ... balanced equation

Reactants are solid iron and solid sulfur

Product is iron(III) sulfide

A. 1.42 moles Fe x 3 moles S/2 moles Fe = 2.13 moles sulfur

B. 2.75 moles S x 2 moles Fe/3 moles S = 1.83 moles iron

Answer:

c

Explanation:

I want to say c cause u got to evaporate water that is deity so u can drink it. but I might be worng

Answer:

b

Explanation:

precipitation is any product of the condensation of atmospheric water vapor that falls under gravitational pull from clouds. The main forms of precipitation include drizzling, rain, sleet, snow, ice pellets, graupel and hail.