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3 years ago

What element is this? How do you know?

1 answer:

4 0

Atom is the most basic unit of matter. They are the general term used to describe pieces of matter. But a different kind of atom makes up an element. A combination of atom of different elements creates a molecule. For example, you have water; it has a chemical formula of H2O. If you separate H from O, you have two atoms. Two atoms for hydrogen and one atom for oxygen. However, they are of different elements. And when you combine them to form H2O, you create a molecule.

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How many moles of ethane (C2H6) would be needed to react with 62.3 grams of oxygen gas?

Black_prince [1.1K]

The combustion of ethane is expressed in the balanced reaction C2H6 + 3.5O2= 2CO2 + 3 H2O. Given the mass of oxygen gas, we get the moles of ethane needed by converting this mass to mole (dividing my 32 g/mol), then multiply by 1/3.5 (stioch ratio) and the molar mass of ethane (30 g/mol). The answer is 16.69 grams ethane.

6 0

3 years ago

[cu(nh3)4]2 forms a blue solution. when concentrated hcl is added to this solution, what color will the solution change to

g100num [7]

<span>[Cu(NH3)4]2+ forms a blue solution. When concentrated HCl is added to this solution, what color will the solution change to yellow.

Reason:
When conc. HCl is added to the solution containing </span>[Cu(NH3)4]2+, Cl- ions will replace NH3 and form [Cu(Cl)4]2- complex. This can be understood for the following reaction:

[Cu(NH3)4]2+ + Cl- ↔ [Cu(Cl)4]2- + NH3

The Cl- ion is a weak field ligand, while NH3 is a strong field ligand. Hence, Cl- will in less splitting of d-orbitals, as compared to NH3. Due to this, photons of different energies will be absorbed by these complexes, and hence they display different colours.

8 0

3 years ago

Read 2 more answers

In a first–order reaction (A → B and rate = k [A]), tripling the concentration of A will have what effect on the reaction rate?

drek231 [11]

Your answer is b just got done doing mine .

3 0

3 years ago

Read 2 more answers

M(8,7) is the midpoint of rs. The coordinates of s are (9,5) what is the coordinates of r

Darya [45]

Answer:

Coordinate or r = (7,9).

Explanation:

Data obtained from the question include the following:

Mid point = (8,7)

Coordinate of S = (9,5)

Coordinate of r =...?

We shall determine the coordinate of r as follow:

Let the coordinate of r be (x2, y2)

Mid point = (x1 + x2)/2 , (y1 + y2)/2

Mid point = (8,7)

Coordinate of S = (9,5)

x1 = 9

y1 = 5

x2 =?

y2 =?

The value of x2 can be obtained as follow:

8 = (x1 + x2)/2

8 = (9 + x2)/2

Cross multiply

9 + x2 = 2 × 8

9 + x2 = 16

Collect like terms

x2 = 16 – 9

x2 = 7

The value of y2 can be obtained as follow:

5 = (y1 + y2)/2

7 = (5 + y2)/2

Cross multiply

5 + y2 = 2 × 7

5 + y2 = 14

Collect like terms

y2 = 14 – 5

y2 = 9

Coordinate of r = (x2, y2)

Coordinate or r = (7,9)

3 0

4 years ago

Heliocentric and Geocentric

bulgar [2K]

Explanation:

heliocentric means having the sun in the middle/center in the solar system

geocentric means having the earth in the middle/center in the solar system

therefore your answers are:

the planets orbit the sun.

in 1543, Nicolaus Copernicus proposed the theory.

the evidence that led people to believe this was when Galileo observed that four moons orbited around Jupiter. in other words, heliocentric.

most of the stars are located in the milky way galaxy.

7 0

3 years ago