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ra1l [238]
2 years ago
15

Why couple should use a method of birth control

Chemistry
1 answer:
Tresset [83]2 years ago
3 0

Answer:

because it will control the birth of a child which can happen alot being overpopulated in the country or world. It also can mange their life and create a small and happy and healthy family.Also the child can get more love and support from their parents if they have less children and it wont be a taruma for the couple as well.  because growing a child can be expensive time costly and really hard.

Explanation:

plz mark me as a brainlest a and thanks my answer

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Stearic acid (C18H36O2) is a fatty acid, a molecule with a long hydrocarbon chain and an organic acid group (COOH) at the end. I
Paha777 [63]

Answer:

There is 9671  Kj of heat released

Explanation:

<u>Step 1:</u> The balanced equation:

C18H36O2(s) + 26O2(g) --> 18CO2(g)+18H2O(g)

This means for 1 mole of C18H36O2 consumed there is 26 moles of O2 needed to produce 18 moles of CO2 and 18 moles of H2O.

<u>Step 2:</u> Calculate the heat of combustion

ΔH (combustion) = [18*(ΔHf of CO2) + 18*(ΔHf of H2O)] - [1*(ΔHf of C18H36O2) + 26*(ΔHf of O2)]

ΔH (combustion) = [18*(-394 kJ/mol) + 18*(-242 kJ/mol)] - [1*(-948 kJ/mol) + 26*(0 kJ/mol)]

ΔH (combustion) = [(-7092 kJ/mol) + (-4356 kJ/mol)] - (-948 kJ/mol)

= -10500 kJ/mol

ΔH (combustion) = heat released / number of moles of stearic acid

<u>Step 3:</u> Calculate moles of stearic acid

moles of stearic acid = mass / Molar mass of stearic acid

moles of stearic acid = 262g / 284.48 g/mole = 0.921 moles

<u>Step 4:</u> Calculate moles of oxygen

moles of O2 = 914.5 / 32g/mole

moles of O2 = 28.578125 moles

Stearic acid is the limiting reactant: it will <u>completely react</u>

There will react 26*0.921 mole = 23.946 mole of O2

This means there will remain 4.63 moles of O2

<u>Step 5:</u> Calculate heat released

q = (ΔH combustion) * (moles of stearic acid) = (-10500 kJ/mol) * (0.921 moles) = 9671 Kj

There is 9671  Kj of heat released

6 0
2 years ago
Estimate the number of moles of water in all the Earth's oceans. Assume water covers 75% of the Earth to an average depth of 3 k
o-na [289]

Answer:

there are approximately n ≈ 10²² moles

Explanation:

Since the radius of the earth is approximately R=6378 km= 6.378*10⁶ m , then the surface S of the earth would be

S= 4*π*R²

since the water covers 75% of the Earth's surface , the surface covered by water Sw is

Sw=0.75*S

the volume for a surface Sw and a depth D= 3 km = 3000 m ( approximating the volume through a rectangular shape) is

V=Sw*D

the mass of water under a volume V , assuming a density ρ= 1000 kg/m³ is

m=ρ*V

the number of moles n of water ( molecular weight M= 18 g/mole = 1.8*10⁻² kg/mole ) for a mass m is

n = m/M

then

n = m/M = ρ*V/M = ρ*Sw*D/M = 0.75*ρ*S*D/M = 3/4*ρ*4*π*R² *D/M = 3*π*ρ*R² *D/M

n=3*π*ρ*R² *D/M

replacing values

n=3*π*ρ*R² *D/M = 3*π*1000 kg/m³*(6.378*10⁶ m)² *3000 m /(1.8*10⁻² kg/mole) = 3*π*6.378*3/1.8 * 10²⁰ = 100.18 * 10²⁰ ≈ 10²² moles

n ≈ 10²² moles

8 0
3 years ago
What is atomic hydrogen?<br>​
goldenfox [79]
A hydrogen atom is an atom of the chemical element hydrogen. The electrically neutral atom contains a single positively charged proton and a single negatively charged electron bound to the nucleus by the Coulomb force. Atomic hydrogen constitutes about 75% of the baryonic mass of the universe.
8 0
3 years ago
Read 2 more answers
Which is an example of making a quantitative observation?
Elanso [62]

Answer:

A) measuring mass of metal used in a reaction

Explanation:

Quantitive observations is data involving statistics and numerical values.

4 0
2 years ago
An ion with 11 protons 12 neutrons and a charge of + 1 has an atomic number of
posledela

Answer:

11 electrons total and 23amu

Explanation:

This tells us that sodium has 11 protons and because it is neutral it has 11 electrons. The mass number of an element tells us the number of protons AND neutrons in an atom (the two particles that have a measurable mass). Sodium has a mass number of 23amu.

5 0
2 years ago
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