How is a kcal or Calorie different from a calorie?

Answer: 445.15 kJ of heat could be obtained by the combustion of 8.0 grams [tex]CH_4[/tex]

Explanation:

To calculate the moles :

[tex]\text{Moles of solute}=\frac{\text{given mass}}{\text{Molar Mass}}[/tex]    

[tex]\text{Moles of} CH_4=\frac{8.0g}{16.04g/mol}=0.50moles[/tex]

The given thermochemical equation is:

[tex]CH_4(g)+2O_2(g)\rightarrow CO_2(g)+2H_2O(g)[/tex]  [tex]\Delta H=890.3kJ[/tex]

According to stoichiometry :

1 mole of [tex]CH_4[/tex] on combustion produce heat = 890.3 kJ

Thus 0.50 moles of [tex]CH_4[/tex] on combustion produce heat =[tex]\frac{890.3}{1}\times 0.50=445.15kJ[/tex]

Thus 445.15 kJ of heat could be obtained by the combustion of 8.0 grams [tex]CH_4[/tex]

Answer:

3.94 L

Explanation:

From the question given above, the following data were obtained:

Mass of O₂ = 5.62 g

Volume of O₂ =?

Next, we shall determine the number of mole present in 5.62 g of O₂. This can be obtained as follow:

Mass of O₂ = 5.62 g

Molar mass of O₂ = 2 × 16 = 32 g/mol

Mole of O₂ =?

Mole = mass / molar mass

Mole of O₂ = 5.62 / 32

Mole of O₂ = 0.176 mole

Finally, we shall determine the volume of 5.62 g (i.e 0.176 mole) of O₂ at STP. This can be obtained as follow:

1 mole of O₂ occupied 22.4 L at STP.

Therefore, 0.176 mole of O₂ will occupy = 0.176 × 22.4 = 3.94 L at STP.

Thus 5.62 g (i.e 0.176 mole) of O₂ occupied 3.94 L at STP

Answer:

The cytoplasm of erythrocytes is rich in hemoglobin, an iron-containing biomolecule that can bind oxygen and is responsible for the red color of the cells and the blood. Each human red blood cell contains approximately 270 million of these hemoglobin molecules.

Explanation:

hope this helps(;

Answer:

Average atomic mass = 19.9 amu

Explanation:

Isotopes can be defined as two or more forms of a chemical element that are made up of equal numbers of protons and electrons but different numbers of neutrons.

Generally, the isotopes of a chemical element have the same chemical properties because of their atomic number but different physical properties due to their atomic weight (mass number).

Given the following data;

Relative abundance of Z-19 = 55%

Relative abundance of Z-21 = 45%

Atomic mass of Z-19 = 19 amu

Atomic mass of Z-21 = 21 amu

To find the average atomic mass;

Average atomic mass = 19 * (55/100) + 21 * (45/100)

Average atomic mass = 19*0.55 + 21*0.45

Average atomic mass = 10.45 + 9.45

Average atomic mass = 19.9 amu

Therefore, the average atomic mass for element Z is 19.9 amu.

Answer:

Do part by part

Explanation:

Explanation:

The equation of the reaction is given as;

Be + 2HCl → BeCl2 + H2

What is the mass of beryllium required to produce 25.0g of beryllium chloride?

1 mol of Be produces 1 mol of BeCl2

Converting to mass;

Mass = Molar mass  *  Number of moles

9.01g of Be produces 79.92g of BeCl2

xg of Be produces 25g of BeCl2

Solving for x;

x = 25 * 9.01 / 79.92

x = 2.82 g

What is the mass of hydrochloric acid required to produce 25.0g of beryllium chloride? g

Converting 25.0g of beryllium chloride to moles;

Number of moles = Mass / Molar mass

Number of moles = 25 / 79.92 = 0.3128 mol

2 mol of HCl produces 1 mol of BeCl2

x mol of HCl would produce 0.3128 mol of BeCl2

solving for x;

x = 0.3128 * 2 = 0.6256 mol

Converting to mass;

Mass = 0.6256 * 36.5 = 22.83 g

What is the mass of hydrogen gas produced when 25.0g of beryllium chloride is also produced? g

25g of BeCl2 = 0.3128 mol of BeCl2

From the equation;

1 mol of H2 is produced alongside 1 mol of BeCl2

This means;

0.3128 mol of H2 would also be produced alongside 0.3128 mol of BeCl2

Mass = Number of moles * Molar mass

Mass = 0.3128mol * 2.0159 g/mol = 0.6306 g

Answer:

N2 (nitrogen) O3 (ozone) CaO (calcium oxide) C6H12O6 (glucose, a type of sugar)

Answer:

dihydrogen monoxide

dinitrogen monosulfide

Answer:

Wheat!

Explanation:

Corn ranks first, Wheat, then Rice!

Answer:

Explanation:

1-butanol has 4 carbon atoms with an OH group at the first carbon atom.

Dichlorodifluoromethane has 1 carbon atom with 2 chlorine atoms and 2 fluorine atoms.

Answer:

c. 2s2 2p5

Explanation:

2s2 2p5 has 7 valence electrons and only needs one electron to complete the octet.  This element will be the most electronegative.

Answer:

6.60 moles of ZnO have 537,108 g.

Explanation:

Answer:

The answer is decline and apparent

Explanation:

I took the test and got it right

Answer:ionic

Explanation:

Answer:

Metal + Oxygen -> Metal Oxide

Explanation:

It's pretty self-explanatory. However, let me show you an example:

Iron + Oxygen -> Iron Oxide

Iron rusts. When iron rusts, it comes in contact with air to form Iron Oxide, which is rust itself.

Answer:

E sound

Explanation:

Answer:

Iron (II) sulfide and oxygen

1100 mmHg

Math

Pre-Algebra

Order of Operations: BPEMDAS

Chemistry

Gas Laws

Stoichiometry

Step 1: Define

[Given] 1.5 atm

[Solve] mmHg

Step 2: Identify Conversions

1 atm = 760 mmHg

Step 3: Convert

Step 4: Check

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

1140 mmHg ≈ 1100 mmHg

Answer:

a. The gas with the highest average molecular speed is the gas option 3.

b, The gas that has the lowest average molecular speed is the gas option 1.

c. The gas with average molecular speed between the highest and the lowest is the gas sample, option 4

Explanation:

From the kinetic theory of gases we have;

[tex]v_{rms} = \sqrt{\dfrac{3\cdot R\cdot T}{m} }[/tex]

Where;

[tex]v_{rms}[/tex] = The root mean square velocity of the gas

T = Temperature of gas in Kelvin

m = Mass of atom or molecule in kilograms

R = The universal gas constant

Therefore, [tex]v_{rms}[/tex] ∝ T and [tex]v_{rms}[/tex] ∝ 1/m

a. Therefore, the gas with the highest average molecular speed has the highest temperature, 'T', and the lowest mass, 'm', therefore, we have;

The gas with the highest average molecular speed is the gas option 3. with only 0.128 moles of Ne in 5.69 L container at a temperature of 426 K

b. The gas with the lowest average molecular speed has the lowest temperature, 'T', and the highest mass, 'm', therefore, we have;

The gas with the lowest average molecular speed is the gas option 1. with only 0.564 moles of Ne in 5.33 L container at a temperature of 308 K

c. The gas with an average molecular speed between the highest and the lowest is the gas with intermediate temperature and mass within the given gas samples

Therefore, the gas with the average molecular speed between the highest and lowest is the gas option 4. with 0.322 moles of Ne in 4.00 L container at a temperature of 398 K

Answer:

it is true because if you subtract 10 - 14 you will get -4 so it is less than 107.

Explanation:

Hope this helps!

Answer:

4.2 Liters (2 sig-figs)

Explanation:

Apply Boyles Law ... P₁V₁ = P₂V₂

P₁ = 712 Torr      P₂ = 3560 Torr

V₁ = 21.0L           V₂ = ?

P₁V₁ = P₂V₂ => V₂ = P₁V₁/P₂ = (712Torr)(21.0L)/(3560Torr) = 4.2 Liters (2 sig-figs)

Answer: 34 gram of chromium produced from 50g of [tex]Cr_2O_3[/tex]

Explanation:

To calculate the moles :

[tex]\text{Moles of solute}=\frac{\text{given mass}}{\text{Molar Mass}}[/tex]    

[tex]\text{Moles of} Cr_2O_3=\frac{50g}{152g/mol}=0.33moles[/tex]

The decomposition of [tex]Cr_2O_3[/tex] follows the equation :

[tex]2Cr_2O_3\rightarrow 4Cr+3O_2[/tex]  

According to stoichiometry :

2 moles of [tex]Cr_2O_3[/tex] produce = 4 moles of [tex]Cr[/tex]

Thus 0.33 moles of [tex]Cr_2O_3[/tex] will produce=[tex]\frac{4}{2}\times 0.33=0.66moles[/tex]  of [tex]Cr[/tex]

Mass of [tex]Cr=moles\times {\text {Molar mass}}=0.66moles\times 52g/mol=34g[/tex]

Thus 34 gram of chromium produced from 50g of [tex]Cr_2O_3[/tex]

Answer:

★ Molecular geometry is described by VSEPR theory, which basically states that electron pairs around a central atom will repel each other, and get as far apart as possible, in three dimensions.

Explanation:

Hope you have a great day :)

Answer:

electrical

Explanation:

i kinda guessed.

Answer:

electrical energy is changed into sound energy

true...as it gives home to many of the organisms