Question 8

Which of the following chemical equations depicts a balanced chemical reaction?

Deffense [45]

Answer:

D.) 2 H₂ + O₂ -----> 2 H₂O

Explanation:

An equation is balanced when there is an equal amount of each element on both sides of the reaction. If these amounts are unequal, coefficients can be added to modify the amount of particular molecules.

A.) Not balanced

2 H₂ + 2 O₂ -----> H₂O

Reactants: 4 hydrogen, 4 oxygen

Products: 2 hydrogen, 1 oxygen

B.) Not balanced

2 H₂ + 2 O₂ -----> 2 H₂O

Reactants: 4 hydrogen, 4 oxygen

Products: 4 hydrogen, 2 oxygen

C.) Not balanced

H₂ + O₂ -----> H₂O

Reactants: 2 hydrogen, 2 oxygen

Products: 2 hydrogen, 1 oxygen

D.) Balanced

2 H₂ + O₂ -----> 2 H₂O

Reactants: 4 hydrogen, 2 oxygen

Products: 4 hydrogen, 2 oxygen

3 0

2 years ago

The water in a 2500-L aquarium contains 1.25 g of copper. Calculate the concentration of copper in the water in ppm (remember 1

lorasvet [3.4K]

Answer:

0.5ppm

Explanation:

Step 1:

Data obtained from the question.

Volume of water = 2500L

Mas of Cu = 1.25 g

Step 2:

Determination of the concentration of Cu in g/L. This is illustrated below:

Volume of water = 2500L

Mas of Cu = 1.25 g

Conc. of Cu In g/L =?

Conc. g/L = Mass /volume

Conc. of Cu in g/L = 1.25/2500

Conc. of Cu in g/L = 5x10^–4 g/L

Step 3:

Conversion of the concentration of Cu in g/L to ppm. This is illustrated below

Recall:

1g/L = 1000mg/L

Therefore, 5x10^–4 g/L = 5x10^–4 x 1000 = 0.5mg/L

Now, we know that 1mg/L is equal to 1ppm.

Therefore, 0.5mg/L is equivalent to 0.5ppm

6 0

4 years ago

When scientists say that a theory can never be proven, what are they actually saying?

Lelu [443]

They are saying that every theory can eventually be changed a bit due to further research. It does not mean the theory is bad, just that it can become better.

6 0

3 years ago

Methane CH4 (g) reacts with oxygen gas to produce carbon dioxide and water. ____________________________________________________

nordsb [41]

Answer: The chemical equations are written below.

Explanation:

For a: Methane reacts with oxygen gas to produce carbon dioxide and water.

Combustion reaction is defined as the reaction in which a hydrocarbon reacts with oxygen gas to produce carbon dioxide and water

The chemical equation for the combustion of methane follows:

$CH_4(g)+2O_2(g)\rightarrow CO_2(g)+2H_2O(g)$

For b: Butane reacts with oxygen gas to produce carbon dioxide and water.

This is also an example of combustion reaction.

The chemical equation for the combustion of butane follows:

$2C_4H_{10}(g)+13O_2(g)\rightarrow 8CO_2(g)+10H_2O(g)$

For c: An aqueous solution of sulfuric acid reacts with aqueous potassium hydroxide to produce potassium sulfate and water.

When an acid reacts with a base, it leads to the formation of salt and water. This reaction is known as neutralization reaction

The chemical equation for the reaction of potassium hydroxide and sulfuric acid follows:

$H_2SO_4+2KOH\rightarrow K_2SO_4+2H_2O$

Hence, the chemical equations are written above.

4 0

4 years ago

You need 2.5 mol of iron (fe) for an experiment. how many grams of iron must you measure out?

padilas [110]

The relationship between the mole and the mass of an element is given by this equation: mass in grams = moles * molar mass of iron
mass of iron needed = 2.5 * 56 = 140g.
Therefore, 140g of iron is needed.

3 0

3 years ago