What are the two types of dichotomous keys. Which is easier to use?

If a gas furnace releases 420 kcal of heat energy, what is the energy in kilojoules? (1 cal = 4.184 J)

Igoryamba

Answer:
The furnace releases 1757280 J

Explanation:
We will do the conversion on two steps:
1- convert the kcal to cal
2- convert the cal to J

Step 1: converting kcal to cal
1 kcal is equivalent to 1000 cal. Therefore:
420 kcal is equivalent to 420*1000 = 420000 cal

Step 2: converting cal to J
We are given that:
<span>1 cal = 4.184 J
</span>Therefore:
420000 cal is equivalent to 420000 * 4.184 = 1757280 J

Hope this helps :)

8 0

3 years ago

compound 1 contains 15.0g of hydrogen and 120.0g oxygen. What is the percent compound of each element?

allsm [11]

Note down the formula below

$\boxed{\sf Mass\%\;of\; element=\dfrac{Mass\:of\:the\: element}{Mass\;of\:the\: compound}\times 100}$

Mass of the compound

$\\ \sf\longmapsto 15+120=135g$

Mass % of Hydrogen:-

$\\ \sf\longmapsto \dfrac{15}{135}\times 100$

$\\ \sf\longmapsto \dfrac{1}{9}\times 100$

$\\ \sf\longmapsto 11.1\%$

Mass % of Oxygen:-

$\\ \sf\longmapsto \dfrac{120}{135}\times 100$

$\\ \sf\longmapsto \dfrac{8}{9}\times 100$

$\\ \sf\longmapsto 88.9\%$

8 0

3 years ago

Which of the following shows the conservation of mass during cellular respiration? 3 CO2 3 H2O energy → 3 C6H12O6 3 O2 6 CO2 6 H

Thepotemich [5.8K]

The reaction that has been, following the law of conservation of mass has been $\rm C_6H_1_2O_6\;+\;6\;O_2\;\rightarrow\;6\;CO_2\;+\;6\;H_2O\;+\;Energy$ .

The law of conservation has been given in the chemical reaction that there has been no loss or gain of the mass and energy.

The law of conservation has been evident when there has been an equal number of atoms of each element on the product and the reactant side.

<h3 /><h3>Conservation of mass in Cellular respiration</h3>

The following reactions have been identified as:

$\rm 3\;CO_2\;+\;3\;H_2O\;+\;Energy\;\rightarrow\;3\;C_6H_1_2O_6$

Carbon atoms

Reactant = 3

Product = 18

Oxygen atoms

Reactant = 9

Product = 18

Hydrogen atoms

Reactant = 6

Product = 36

The number of atoms is not equal on the product and reactant side, thus not follows the law of conservation of mass.

$\rm 3\;O_2\;+\;6\;CO_2\;+\;6\;H_2O\;+\;Energy\;\rightarrow\;C_6H_1_2O_6\;+\;6\;O_2$

Carbon atoms

Reactant = 6

Product = 6

Oxygen atoms

Reactant = 24

Product = 18

Hydrogen atoms

Reactant = 12

Product = 12

The number of atoms is not equal on the product and reactant side, thus not follows the law of conservation of mass.

$\rm C_6H_1_2O_6\;+\;6\;O_2\;\rightarrow\;6\;CO_2\;+\;6\;H_2O\;+\;Energy$

Carbon atoms

Reactant = 6

Product = 6

Oxygen atoms

Reactant = 18

Product = 18

Hydrogen atoms

Reactant = 12

Product = 12

The number of atoms is equal on the product and reactant side, thus follows the law of conservation of mass.

$\rm 6\;H_2O\;+\;C_6H_1_2O_6\;\rightarrow\;6\;O_2\;+\;Energy$

Carbon atoms

Reactant = 6

Product = 0

Oxygen atoms

Reactant = 12

Product = 12

Hydrogen atoms

Reactant = 24

Product = 0

The number of atoms is not equal on the product and reactant side, thus not follows the law of conservation of mass.

Thus, the reaction that has been following the law of conservation of mass has been $\rm C_6H_1_2O_6\;+\;6\;O_2\;\rightarrow\;6\;CO_2\;+\;6\;H_2O\;+\;Energy$ .

Learn more about law of conservation, here:

brainly.com/question/2175724

4 0

2 years ago

itrogen forms a number of different compounds with oxygen, depending upon the experimental conditions. This type of observation

statuscvo [17]

Answer:

the Law of multiple proportions

Explanation:

The law of multiple proportions states that, if two elements A and B combine to form more than one chemical compound, then the various masses of one of the elements A, which combines with a fixed mass of the element B are in simple multiple ratio.

This is demonstrated in the formation of nitrogen compounds such as NO and N2O when nitrogen combines with oxygen. This ratio is always constant.

5 0

2 years ago

PLSSS HELPPPPPPPP. I will give brainliest

nasty-shy [4]

Answer:

Ionic bond

Explanation:

Covalent bonds can only form between non-metals and copper is a metal so it would be an ionic bond.

6 0

2 years ago