If 20.0g of water at 56.2℃ absorbs 195 J of heat, what is the final temperature? *

The equation for the reaction between copper and nitric acid is vCu + wHNO3--->xCu(NO3)2 + yNO + zH2O Balance the equation an

lana [24]

Answer:

The coefficients of the balanced equation are:

v= 1
w= 4
x= 1
y= 2
z=2

Explanation:

The Law of Conservation of Matter, also called the Law of Conservation of Mass or the Lomonósov-Lavoisier Law, postulates that "mass is neither created nor destroyed, it is only transformed". This means that the reagents interact with each other and form new products with different physical and chemical properties than the reagents, but the amount of matter or mass before and after a transformation (chemical reaction) is always the same. In other words, then the mass before the chemical reaction is equal to the mass after the reaction.

Then, you must balance the following chemical equation:

v Cu + w HNO₃ → x Cu(NO₃)₂ + y NO + z H₂O

For that, you must first look at the subscripts next to each atom to find the number of atoms in the equation. If the same atom appears in more than one molecule, you must add its amounts

Left side: 1 copper, 1 hydrogen, 1 nitrogen and 3 oxygen.
Right side: 1 copper, 2 hydrogen, 3 nitrogen and 8 oxygen.

The coefficients located in front of each molecule indicate the amount of each molecule for the reaction. This coefficient can be modified to balance the equation, just as you should never alter the subscripts.

By multiplying the coefficient mentioned by the subscript, you get the amount of each element present in the reaction.

Generally, hydrogen and oxygen balance in the end. So you balance nitrogen first, because copper is already balanced (there is the same amount on both sides of the reaction). If w = 2, then:

Left side: 1 copper, 2 hydrogen, 2 nitrogen and 6 oxygen.
Right side: 1 copper, 2 hydrogen, 3 nitrogen and 8 oxygen.

But you see then that the oxygen is unbalanced and you have less quantity in the reagents. Then w must be greater. Being w = 4:

Left side: 1 copper, 4 hydrogen, 4 nitrogen and 10 oxygen.
Right side: 1 copper, 2 hydrogen, 3 nitrogen and 8 oxygen.

Going back to the idea of balancing nitrogen, being y = 2:

Left side: 1 copper, 4 hydrogen, 4 nitrogen and 10 oxygen.
Right side: 1 copper, 2 hydrogen, 4 nitrogen and 9 oxygen.

Balancing the hydrogen, being z = 2:

Left side: 1 copper, 4 hydrogen, 4 nitrogen and 10 oxygen.
Right side: 1 copper, 4 hydrogen, 4 nitrogen and 10 oxygen.

Since you have the same amount of each element on each side of the reaction, the reaction is balanced. Then, the balanced equation is:

Cu + 4 HNO₃ → Cu(NO₃)₂ + 2 NO + 2 H₂O

Finally:

v= 1
w= 4
x= 1
y= 2
z=2

6 0

3 years ago

which quantity can be calculated for a solid compound, given only the formula of the compound and the Periodic Table of elements

Kryger [21]

You can calculate the gram formula mass of this compound by adding the atomic mass of every element in this compound according to the periodic table of elements.

7 0

3 years ago

The comparison of the masses of equal volumes of material is also defined as

Yuri [45]

Density, I am pretty sure this is the correct answer.

8 0

3 years ago

During World War One, observation balloons were used in order to spy out enemy positions. An observation

blondinia [14]

Answer:

0.971

Explanation:

The pressure (P) in atmospheres (atm) the balloon was filled to will be

P = P1 +P2 + P3

where P1 is the pressure in atm of Helium (0.5 atm)

P2 is the pressure in atm of Nitrogen (X atm)

P3 is the pressure in atm of Hydrogen (0.4 atm)

The value of P2 provided in the question is in mmHg

To convert we have

1 atm = 760 mmHg

X atm = 54 mmHg

X = 54 × 1/760

X = 0.071 atm

Hence, P2 = 0.071 atm

Thus, from the formula earlier

P = 0.5 + 0.071 + 0.4

P = 0.971 atm

7 0

3 years ago

How many formula units of silver fluoride, AgF, are equal to 42.15 g of this substance?

Wittaler [7]

Answer:

2.05 × 10²³ formula units

Explanation:

Given data:

Mass of AgF = 43.15 g

Number of formula units = ?

Solution:

Number of moles of AgF:

Number of moles = mass/ molar mass

Number of moles = 43.15 g/ 126.87 g/mol

Number of moles = 0.34 mol

Now Number of formula units will be determine by using Avogadro number.

It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.

The number 6.022 × 10²³ is called Avogadro number

1 mole = 6.022 × 10²³ formula units

0.34 mol × 6.022 × 10²³ formula units

2.05 × 10²³ formula units

4 0

4 years ago

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