Where is the majority of Earth’s water found? glaciers

Research is being carried out on cellulose as a source of chemicals for the production of fibers, coatings, and plastics. Cellul

Luden [163]

Answer:

+ 636 KJ

Explanation:

We want to arrive to the equation

C6H12O6(s) ---------> 6 H2CO(g) ΔH ° rxn = ?

by manipulating algebraically the first four given equations.

We notice the first one has our product H2CO(g) as a reactant. This indicates we must take the inverse of that equation. Also we need 6 mol of H2CO(g), thus it also needs to be multiplied by 6

6 CO2(g) + 6 H2O(g) ------->6H2CO(g) + 6O2(g) ΔH °comb = + 572.9 KJ/x 6

Now we want C6H12O6(s) as a reactant and it is a product in the second one, therefore lets reverse it

C6H12O6(s) -------> 6 C(s) + 6 H2(g) + 3 O2(g) ΔH ° f = + 1274.4 KJ/mol

Now if take the third equation and multiply it by six we will cancel the C(s) with the above equation

6 C(s) + 6O2(g) ---------> 6 CO2(g) ΔH ° f = - 393.5 KJ/mol x 6

Finally by multiplying the last equation by 6 and adding all the equations we will arrive at our desired one

6 H2(g) + 3 O2(g) -----------> 6H2O(g) ΔH ° f = - 285.8 KJ/mol x 6

then lets add them to get ΔH ° rxn:

6 CO2(g) + 6 H2O(g) ------->6H2CO(g) + 6O2(g) ΔH °comb = + 3437.4 KJ

+ C6H12O6(s) -------> 6 C(s) + 6 H2(g) + 3 O2(g) ΔH ° f = + 1274.4 KJ

+ 6C(s) + 6O2(g) ---------> 6 CO2(g) ΔH ° f = - 2361.0 KJ

+6 H2(g) + 3 O2(g) -----------> 6H2O(g) ΔHº f = - 1714.8 KJ

C6H12O6(s) ---------> 6 H2CO(g)

ΔH ° rxn = 3437.4 + 1274.4 - 2361.0 - 1714.8 = 636 KJ

8 0

3 years ago

Which element will have the greatest attraction for the calcium electrons?

ratelena [41]

Its would be fluorine as its the most electronegative

hope that helps

6 0

4 years ago

Question 1-19

Hunter-Best [27]

The experiment involving the determination of the number of ice cubes required to keep the temperature of the glass under 15 degrees Celcius, the following things have to be kept in mid:

The temperature of the surroundings
The initial temperature of the glass
The number of ice cubes added to the water in the glass

In order to keep into consideration the changing environmental temperatures (which is a variable in the experiment), the experiment had to be conducted daily to get accurate results keeping into consideration all the factors.

brainly.com/question/11256472

7 0

2 years ago

Now they feel it is best to have you identify an unknown gas based on its properties. Suppose 0.508 g of a gas occupies a volume

pishuonlain [190]

Answer: Option (b) is the correct answer.

Explanation:

The given data is as follows.

mass = 0.508 g, Volume = 0.175 L

Temperature = (25 + 273) K = 298 K, P = 1 atm

As per the ideal gas law, PV = nRT.

where, n = no. of moles = $\frac{mass}{\text{molar mass}}$

Hence, putting all the given values into the ideal gas equation as follows.

PV = $\frac{mass}{\text{molar mass}} \times RT$

1 atm \times 0.175 L = $\frac{0.508 g}{\text{molar mass}} \times 0.0821 L atm/ K mol \times 298 K$

= 71.02 g

As the molar mass of a chlorine atom is 35.4 g/mol and it exists as a gas. So, molar mass of $Cl_{2}$ is 70.8 g/mol or 71 g/mol (approx).

Thus, we can conclude that the gas is most likely chlorine.

4 0

3 years ago

In an acid-base titration,

Lemur [1.5K]

Answer:

b

Explanation:

An acid-base titration is an experimental procedure used to determined the unknown concentration of an acid or base by precisely neutralizing it with an acid or base of known concentration. ... It is filled with a solution of strong acid (or base) of known concentration.

7 0

3 years ago