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2 years ago

since an element always has a different number of protons, the mass can indicate how many neutrons are in an isotope

Chemistry

1 answer:

elena-s [515]2 years ago

8 0

Answer:

The number of protons is equal to the mass number of the element. Since an element always has a different number of protons, the mass can indicate how many neutrons are in an isotope. Atoms of the same element can have a different number of neutrons. There are three naturally-occurring isotopes of carbon.

Explanation:

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Research is being carried out on cellulose as a source of chemicals for the production of fibers, coatings, and plastics. Cellul

Luden [163]

Answer:

+ 636 KJ

Explanation:

We want to arrive to the equation

C6H12O6(s) ---------> 6 H2CO(g) ΔH ° rxn = ?

by manipulating algebraically the first four given equations.

We notice the first one has our product H2CO(g) as a reactant. This indicates we must take the inverse of that equation. Also we need 6 mol of H2CO(g), thus it also needs to be multiplied by 6

6 CO2(g) + 6 H2O(g) ------->6H2CO(g) + 6O2(g) ΔH °comb = + 572.9 KJ/x 6

Now we want C6H12O6(s) as a reactant and it is a product in the second one, therefore lets reverse it

C6H12O6(s) -------> 6 C(s) + 6 H2(g) + 3 O2(g) ΔH ° f = + 1274.4 KJ/mol

Now if take the third equation and multiply it by six we will cancel the C(s) with the above equation

6 C(s) + 6O2(g) ---------> 6 CO2(g) ΔH ° f = - 393.5 KJ/mol x 6

Finally by multiplying the last equation by 6 and adding all the equations we will arrive at our desired one

6 H2(g) + 3 O2(g) -----------> 6H2O(g) ΔH ° f = - 285.8 KJ/mol x 6

then lets add them to get ΔH ° rxn:

6 CO2(g) + 6 H2O(g) ------->6H2CO(g) + 6O2(g) ΔH °comb = + 3437.4 KJ

+ C6H12O6(s) -------> 6 C(s) + 6 H2(g) + 3 O2(g) ΔH ° f = + 1274.4 KJ

+ 6C(s) + 6O2(g) ---------> 6 CO2(g) ΔH ° f = - 2361.0 KJ

+6 H2(g) + 3 O2(g) -----------> 6H2O(g) ΔHº f = - 1714.8 KJ

C6H12O6(s) ---------> 6 H2CO(g)

ΔH ° rxn = 3437.4 + 1274.4 - 2361.0 - 1714.8 = 636 KJ

8 0

3 years ago

Carbohydrates like sugars and starches are made of only three elements: carbon (C), hydrogen (H), and oxygen (O). How is it poss

lara31 [8.8K]

Answer:

See explanation

Explanation:

A carbohydrate is formed from carbon, hydrogen and oxygen. These three elements are combined in every carbohydrate.

Even though carbohydrates are composed of only these three atoms, the number of atoms of these elements in each carbohydrate as well as the spatial arrangement of these atoms in each carbohydrate is not the same.

This means that different carbohydrates contain different number of carbon, oxygen and hydrogen atoms which are arranged in different ways in space. This gives room for the existence of many different types of carbohydrates all consisting of carbon, hydrogen and oxygen atoms.

8 0

2 years ago

How many molecules are in 2.50 moles of SO2

dusya [7]

Every compound or element has a fixed number of molecules per mole. This is given by the Avogadros number which is about 6.022 x 10^23 molecules per mole. Therefore:

molecules = 2.50 moles * (6.022 x 10^23 molecules / mole)

<span>molecules = 1.5055 x 10^24 molecules of SO2</span>

7 0

2 years ago

The image shows a projection map.

meriva

A. Flat model, Mercator projection

4 0

2 years ago

6. The fusion of 4 H-1 nuclei to produce two positrons and one other nuclei.

KIM [24]

Explanation:

Normally, fusion involves two heavy hydrogen nuclides but since we have 4 light hydrogen nuclides, two of which underwent positron emission, thus changing two protons into neutrons plus 2 positrons and 2 neutrinos. The resulting nucleus from this fusion reaction is an He-4 nucleus.

3 0

2 years ago