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Oliga [24]
3 years ago
12

What is the primary source of energy in most living communities?

Chemistry
1 answer:
klasskru [66]3 years ago
4 0

Answer:

The sun

Explanation:

The sun is the primary source of energy in most living communities. The producers or the green plants that prepare their own food by the use of sunlight and other natural resources. Carbon dioxide, water, and other minerals are used by the plants to make their food in the presence of chlorophyll. Plants are then consumed by the consumers. This chain helps in forming the food chain and the food web.

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Problem page a virus has a mass of ×9.010−12mg and an oil tanker has a mass of ×3.0107kg . use this information to answer the qu
faltersainse [42]
A. The mass of one mole of the virus is calculated by multiplying the mass of a single virus by the Avogadro's number which is equal to 6.022 x 10^23. Performing this operation,

   mass = (9.0 x 10^-12 mg)(6.022 x 10^23) = 5.42 x 10^12 mg

In correct number of significant figures, the answer would only have to be 5.4 x 10^12 mg. 

b. The number of moles of the virus that will have the same mass as the oil tanker is calculated by dividing the mass of the oil tanker by the mass of one mole of the virus. Note that doing division, both would have to have the same units. 

       n = (3.0 x 10^7 kg) / (5.4 x 10^12 mg)(1 g/1000 mg)(1 kg/1000 g)

Simplifying,
               n = 6

In correct number of significant figures, the answer is 6.0. 
4 0
3 years ago
Read 2 more answers
What happens if 2 hydrogen and 1 oxygen atoms are combined?
Wittaler [7]

Hello There!

We will have water (H2O)

So if you drink a glass of water, you drink a glass of H2O.

Hope it helps! :)

GraceRosalia here to help you :)

8 0
2 years ago
Read 2 more answers
Can someone help, please ??
Bumek [7]
Concentrated I believe
8 0
2 years ago
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The isotope of an atom containing 31 protons and 39 neutrons suddenly has two neutrons added to it.
xxTIMURxx [149]

Answer:

Gallium-72

Explanation:

The elements are identified by the number of protons of the atom, which is its atomic number.

In this case the number of protons 39 (atomic number 39) permit you to identify the element as gallium.

Now, to identify the isotope you tell the name of the element and add the mass number.

The mass number is the sum of the protons and the neutrons

In this case, the number of neutrons is the original 39 plus the 2 added suddenly, i.e. 39 + 2 = 41, so the mass number is 31 + 41 = 72

Therefore, the isotope is gallium - 72.

3 0
2 years ago
Use the given data at 500 K to calculate ΔG°for the reaction
Anton [14]

Answer : The  value of \Delta G^o for the reaction is -959.1 kJ

Explanation :

The given balanced chemical reaction is,

2H_2S(g)+3O_2(g)\rightarrow 2H_2O(g)+2SO_2(g)

First we have to calculate the enthalpy of reaction (\Delta H^o).

\Delta H^o=H_f_{product}-H_f_{reactant}

\Delta H^o=[n_{H_2O}\times \Delta H_f^0_{(H_2O)}+n_{SO_2}\times \Delta H_f^0_{(SO_2)}]-[n_{H_2S}\times \Delta H_f^0_{(H_2S)}+n_{O_2}\times \Delta H_f^0_{(O_2)}]

where,

\Delta H^o = enthalpy of reaction = ?

n = number of moles

\Delta H_f^0 = standard enthalpy of formation

Now put all the given values in this expression, we get:

\Delta H^o=[2mole\times (-242kJ/mol)+2mole\times (-296.8kJ/mol)}]-[2mole\times (-21kJ/mol)+3mole\times (0kJ/mol)]

\Delta H^o=-1035.6kJ=-1035600J

conversion used : (1 kJ = 1000 J)

Now we have to calculate the entropy of reaction (\Delta S^o).

\Delta S^o=S_f_{product}-S_f_{reactant}

\Delta S^o=[n_{H_2O}\times \Delta S_f^0_{(H_2O)}+n_{SO_2}\times \Delta S_f^0_{(SO_2)}]-[n_{H_2S}\times \Delta S_f^0_{(H_2S)}+n_{O_2}\times \Delta S_f^0_{(O_2)}]

where,

\Delta S^o = entropy of reaction = ?

n = number of moles

\Delta S_f^0 = standard entropy of formation

Now put all the given values in this expression, we get:

\Delta S^o=[2mole\times (189J/K.mol)+2mole\times (248J/K.mol)}]-[2mole\times (206J/K.mol)+3mole\times (205J/K.mol)]

\Delta S^o=-153J/K

Now we have to calculate the Gibbs free energy of reaction (\Delta G^o).

As we know that,

\Delta G^o=\Delta H^o-T\Delta S^o

At room temperature, the temperature is 500 K.

\Delta G^o=(-1035600J)-(500K\times -153J/K)

\Delta G^o=-959100J=-959.1kJ

Therefore, the value of \Delta G^o for the reaction is -959.1 kJ

3 0
3 years ago
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