Please help me! U will get a 30 points!

Answer:

I believe the answer would be chemical reaction.

Answer:

B

Explanation:

Answer:

0.0000101 grams.

Explanation:

First of all, use Avogadro's number to convert from molecules to moles.

Avogadro's number is 6.02 x 10^23.

Second of all, to convert from moles to grams, find the substance formula of phosphorus trichloride. After finding the substance formula, then find the molar mass of phosphorus trichloride.

Phosphorus trichloride is PCl3

Now find the molar mass of PCl3

P = 31.0 amu

Cl = 35.5 amu

They are three chlorine atoms and one phosphorus atom. So you do this.

31.0(1) + 35.5(3) = 137.5 g/mol

Now use dimensional analysis to show your work

4.6 x 10^16 grams of PCl3 * 1 mol/ 6.02 x 10^23 * 137.5 g/mol / 1 mol

The grams and the moles cancel out.

So now do [(4.6 x 10^16) / (6.02 x 10^23)] x 137.5

and you will get 0.000010507

4.6 has the fewest digits which is 2.

So use sig figs and the answer rounds to the nearest millionths.

0.000010507 rounds to 0.0000101

So the final answer is 0.0000101 grams(don't forget the units)

Hope it helped!

Answer: I think that trains move faster then cars! Buttt, The trains are much stronger and bigger, then cars or trucks. Even if they move slowly they can still crush something smaller then them.

Explanation: ( didnt really understand the question, but i tried)

Answer:

No one will precipitated because these all are soluble in water

Explanation:

2KNO3 + FeSO4 -----> K2SO4 + Fe(NO3)2

Answer:

There are 1.4754246675000002e+24 atoms of Hydrogen within the measurement of 2.45 moles of hydrogen!

Explanation:

Answer:

Only reaction 1

Explanation:

C + O2 → CO

the charge of C in CO is +2 (oxidation)

from 0 to +2

the charge of O in CO is -2 (reduction)

from 0 fo -2

Hence it is a redox (reduction-oxidation) reaction

This is also valid for,

C + O2 → CO2

the charge of C in CO2 is +4 (oxidation)

charge increases from 0 to +4

the charge of O in CO2 is -2 (reduction)

charge decreases from 0 to -2

hence, it is a redox reaction

K2SO4 + CaCl → KCl + CaSO4

none of the charges changes in this reaction

please recheck, for this may not be the correct answer

Answer:

278.1g/mol

Explanation:

To find the molar mass of the given compound, we must know the atomic mass of the elements within the compound.

Atomic mass of Mg = 24.3g/mol

Atomic mass of I  = 126.9g/mol

So;

  Molar mass  = 24.3 + 2(126.9) = 278.1g/mol

The molar mass of the compound is  278.1g/mol

Answer:

Lemon Juice - Acid

Baking Soda - Base

Ammonia - Base

Vinegar - Acid

Answer:

Pb(OH)2 + 2 HCl ---> 2H2o + PbCl2

Explanation:

Answer:

A is the closest thing. You change the composition of the steak. You don't in any of the others.

Explanation:

Usually when you cook something, you are doing something to the composition of the object being cooked. A steak might not be obvious, but boiling an egg should be.

Chopping a tree is something physical. You are removing mass in such a way that the tree will fall. There's nothing chemical about that.

Heating a cup of tea looks like it might be chemical. After all steam is sometimes given off which looks like it is chemical. It's not. The water in the tea is just changing phase.

Drying clothes in a dryer. Again, this looks like something might have changed. After all the mass of the clothes just became less. But all you are doing is separating two masses (leaving one of them behind).

Answer:

Water can be used as the thermometric liquid. It expands and contracts with temperature so it can be used. It's just not a very good choice because: It's thermal expansion is not very large compared to other liquids like mercury.

Explanation:

Hope this help

Answer:

its the last one

Answer:

D

Explanation:

Answer:

Cr2O3

Explanation:

To find the empirical formula, which is the smallest whole number ratio of a compound, the following is done:

68.4% Cr = 68.4g of Chromium

31.6% O = 31.6g of Oxygen

Since, Cr = 52, O = 16, divide each mass by their respective atomic mass to convert to moles.

Cr = 68.4/52 = 1.315 mol

O = 31.6/16 = 1.975 mol

- Next, we divide each mole value by the smallest value (1.315mol)

Cr = 1.315/1.315 = 1

O = 1.975/1.315 = 1.50

The ratio or Cr to O is 1:1.5

We multiply this ratio by 2 to get the whole number ratio as follows:

2 × 1: 2 × 1.5

2:3

Hence, the empirical formula of Cr and oxygen is Cr2O3.

Answer:

They form the covering of all body surfaces, line body cavities and hollow organs, and are the major tissue in glands. They perform a variety of functions that include protection, secretion, absorption, excretion, filtration, diffusion, and sensory reception

Explanation:

They form the covering of all body surfaces, line body cavities and hollow organs, and are the major tissue in glands. They perform a variety of functions that include protection, secretion, absorption, excretion, filtration, diffusion, and sensory reception

Answer:

Common strong acids include hydrochloric acid, sulfuric acid, phosphoric acid, and nitric acid. Common weak acids include acetic acid, boric acid, hydrofluoric acid, oxalic acid, citric acid, and carbonic acid.

Answer:

O energy is quantized

Explanation:

Bohr's model of that atom attempts to explain the idea that energy is quantized within an atomic space.

The answer is False.

Explanation:

The amount of rainfall would have the greatest impact on the amount of water available for people in this area. The more the rainfall the more water soaks through layers of porous rocks.Hence, level of water table will remain sufficient for easy pumping of water to the homes.Texas receives plenty of rainfall in a year.In a single year the region can receive up to 48 inches (1,200 mm) of precipitation, and flooding is common near rivers and in low-lying areas. Therefore water table remains intact throughout the year.

Answer:

13

Explanation:

There are 13 moles O in a mole of Ca5(PO4)3OH because there are 13 oxygen atoms in every molecule of Ca5(PO4)3OH. Convert moles oxygen to number of atoms of oxygen. One mole is 6.022*10^23, so your conversion factor would be 6.022*10^23 atoms O/mol O.

Answer:

Star B

Explanation:

Star B, this is because, usually in the discussions about stars, the more luminous star or say, the brighter star usually is the one that possesses the smaller absolute brightness.

That being said, succinctly put, if we have two stars A and star B, if star A is brighter than star B, then star A has a lower absolute brightness. Also, if star B is less brighter than star A, then it has the higher absolute brightness.

Answer:

STAR B

Explanation:

Answer:

3,938.22

Explanation:

(correct me if I'm wrong)

Answer:

How to Draw a Lewis Structure.

Step 1: Find the Total Number of Valence Electrons.

Step 2: Find the Number of Electrons Needed to Make the Atoms "Happy".

Step 3: Determine the Number of Bonds in the Molecule.

Step 4: Choose a Central Atom.

Step 5: Draw a Skeletal Structure.

Step 6: Place Electrons Around Outside Atoms.

Explanation:

Hope this helped! :)

A solution is oversaturated,Which could be done to decrease the oversaturation?

dilute the solution

add more solute

cool the solution

add a different solute

Answer:

AAAAAAAAAAAAA  i just finished the exam

Explanation:

Answer:

Mass over Volume........

Answer:

Number of moles  = 0.01 mole

Explanation:

Given data:

Volume of gas = 0.1 L

Number of moles = ?

Temperature of gas = 25.0°C

Pressure of gas = 2.50 atm

Solution:

The given problem will be solve by using general gas equation,

PV = nRT

P= Pressure

V = volume

n = number of moles

R = general gas constant = 0.0821 atm.L/ mol.K  

T = temperature in kelvin

Now we will convert the temperature.

25+273K = 298 K

by putting values,

2.50 atm × 0.1 L = n × 0.0821 atm.L/ mol.K  × 298 K

0.25 atm.L = n × 24.47atm.L/ mol

n = 0.25 atm.L /24.47atm.L/ mol

n = 0.01 mol

Explanation:

[tex]\tt{2S+6O_2\implies{2SO_3} }[/tex]