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2 years ago

What role do the coefficients serve in a chemical reaction?

2 answers:

7 0

First one. Coefficients are numbers that balance the equation, just like if there is an equation in math where 1=2, you need to multiply 1 by 2 to make that equation true. That's a nice jingle you can remember.

Mariana [72]2 years ago

5 0

It’s not the first one. While it is true that the coefficients balance the equation in terms of conservation, it is not true that this follows the law of conservation of energy. It instead follows the law of conservation of mass.

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How many grams of NH3 can be prepared from 85.5 grams of N2 and 17.3 grams of H2 ?

Tcecarenko [31]

N2 + 3H2 ---> 2NH3

mass of N2 = 28g
mass of H2 = 2g
mass of NH3 = 17g

according to the reaction:
28g N2----------------- 3*2g H2
85,5g N2-------------------- x
x = 18,32g H2 >>> so, nitrogen is excess

according to the reaction:
2*3g H2---------------------- 2*17g NH3
17,3g H2 ------------------------- x
x = 98,03g NH3

<u>answer: 98,03g of NH3</u>

4 0

2 years ago

When an electron of an atom falls from a higher energy level to the ground state, the atom loses 9.4145 x 10-25 joules of energy

Ann [662]

$E = \frac{hc}{wavelength} 
$
given E = 9.4145E-25
h = 6.626E-34
c = 2.998E8
sub values into the equation above, and solve for wavelength.
You will get 0.211m

3 0

2 years ago

Read 2 more answers

Combined gas law problem: a balloon is filled with 500.0 mL of helium at a temperature of 27 degrees Celsius and 755 mmHg. As th

Papessa [141]

The statement of the combined gas law for a fixed amount of gas is,
PV/T = constant
Here, the units of pressure and volume must be consistent and the temperature must be the absolute temperature (Kelvin or Rankine).
0.65 atm is equivalent to 494 mmHg
Using the equation:
(755 x 500) / (27 + 273) = (494 x V) / (-33 + 273)
V = 3396 ml = 3.4 liters

8 0

2 years ago

How many grams of NH3 can be prepared from the synthesis of 77.3 grams of nitrogen and 14.2 grams of hydrogen gas?

lbvjy [14]

Answer:

80.41 g

Explanation:

Data Given:

Mass of Nitrogen (N₂) = 77.3 g

Mass of Hydrogen (H₂) = 14.2 g

many grams of NH₃ = ?

Solution:

First we look at the balanced synthesis reaction

N₂ + 3 H₂ ------—> 2 NH₃

1 mol 3 mol

As 1 mole of Nitrogen react with 3 mole of hydrogen

Convert moles to mass

molar mass of N₂ = 2(14) = 28 g/mol

molar mass of H₂ = 2(1) + 2 g/mol

Now

N₂ + 3 H₂ ------—> 2 NH₃

1 mol (28 g/mol) 3 mol(2g/mol)

28 g 6 g

28 grams of N₂ react with 6 g of H₂

if 28 grams of N₂ produces 6 g of H₂ so how many grams of N₂ will react with 14.2 g of H₂.

Apply Unity Formula

28 g of N₂ ≅ 6 g of H₂

X g of N₂ ≅ 14.2 g of H₂

Do cross multiply

X g of N₂ = 28 g x 14.2 g / 6 g

X g of N₂ = 66.3 g

As we have given with 77. 3 g of N₂ but from this calculation we come to know that 66.3 g will react with 14.2 g of hydrogen and the remaining 10 g N₂ will be in excess

So, Hydrogen is limiting reactant in this reaction and the amount of NH₃ depends on the amount of hydrogen.

Now

To find mass of NH₃ we will do following calculation

Look at the reaction

As we Know

N₂ + 3 H₂ ------—> 2 NH₃

6 g 2 mol

So, 6 g of hydrogen gives 2 moles of NH₃, then how many moles of NH₃ will be produce by 14.2 g

Apply Unity Formula

6 g of H₂ ≅ 2 mol of NH₃

14.2 g of H₂ ≅ X mol of NH₃

Do cross multiply

X mol of NH₃= 14.2 g x 2 mol / 6 g

X mol of NH₃ = 4.73 mol

So, 14.2 g of hydrogen gives 4.73 moles of NH₃

Now

Convert moles of NH₃ to mass

Formula will be used

mass in grams = no. of moles x molar mass . . . . . . (2)

Molar mass of NH₃

Molar mass of NH₃ = 14 + 3(1)

Molar mass of NH₃ = 14 + 3 = 17 g/mol

Put values in equation 2

mass in grams = 4.73 mole x 17 g/mol

mass in grams = 80.41 g

mass of NH₃= 80.41 g

3 0

2 years ago

A metal sample is heated and placed into the water in a calorimeter at room temperature. Which statement best describes how the

andre [41]

Answer:

Energy transfers from the metal to the water and calorimeter until they are all at room temperature.

Explanation:

CHECK THE COMPLETE QUESTION BELOW;

A metal sample is heated and placed into the water in a calorimeter at room temperature. Which statement best describes how the calorimeter can be used to determine the specific heat capacity of the metal sample?

Energy transfers to the metal from the water and calorimeter until they are all at room temperature

. Energy transfers from the metal to the water and calorimeter until they are all at room temperature.

Energy transfers to the metal from the water and calorimeter until they all reach a single temperature.

Energy transfers from the metal to the water and calorimeter until they all reach a single temperature.

EXPLANATION;

Using calorimeter to determine the specific heat capacity of the metal sample can be associated to the theory of conservation of energy because heat which is a form of energy is been transfer of heat between the metal to the water and the calorimeter, this process will proceed till single temperature is attained.

The change in the amount of temperature of the water in the calorimeter is measured in order to get the difference in heat change of the calorimeter water.

CHANGE IN HEAT CAN BE CALCULATED USING THE FORMULA.

Q = cmΔT where Q is the change in heat , c is the specific heat capacity and ΔT is the change in temperature

6 0

2 years ago