Which of these measurements is expressed as three significant figures?

Find the number of moles of water that can be formed if you have 170 mol of hydrogen gas and 80 mol of oxygen gas. Express your

Sav [38]

Answer: The amount of water that can be formed is 160 moles

Explanation:

We are given:

Moles of hydrogen gas = 170 moles

Moles of oxygen gas = 80 moles

The chemical equation for the reaction of hydrogen gas and oxygen gas follows:

$2H_2+O_2\rightarrow 2H_2O$

By Stoichiometry of the reaction:

1 mole of oxygen gas reacts with 2 moles of hydrogen gas

So, 80 moles of oxygen gas will react with = $\frac{2}{1}\times 80=160mol$ of hydrogen gas

As, given amount of hydrogen gas is more than the required amount. So, it is considered as an excess reagent.

Thus, oxygen gas is considered as a limiting reagent because it limits the formation of product.

By Stoichiometry of the reaction:

1 mole of oxygen gas produces 2 moles of water

So, 80 moles of oxygen gas will produce = $\frac{2}{1}\times 80=160moles$ of water

Hence, the amount of water that can be formed is 160 moles

3 0

3 years ago

Metion two common types of flames and conditions under which each is produced

wariber [46]

Answer:

natural flame,oxidising flame

7 0

3 years ago

Gallium is produced by the electrolysis of a solution obtained by dissolving gallium oxide in concentrated NaOH(aq). Calculate t

Alina [70]

Answer: The mass of gallium produced by the electrolysis is 0.0354 grams.

Explanation:

The equation for the deposition of Ga(s) from Ga(III) solution follows:

$Ga^{3+}(aq.)+3e^-\rightarrow Ga(s)$

To calculate the total charge, we use the equation:

$C=I\times t$

where,

C = charge

I = current = 0.490 A

t = time required (in seconds) = $50\times 60=300s$ (Conversion factor: 1 min = 60 s)

Putting values in above equation, we get:

$C=0.490\times 300=147C$

To calculate the moles of electrons, we use the equation:

$\text{Moles of electrons}=\frac{C}{F}$

where,

C = charge = 147 C

F = Faradays constant = 96500

$\text{Moles of electrons}=\frac{147}{96500}=1.52\times 10^{-3}mol$

Now, to calculate the moles of gallium, we use the equation:

$\text{Moles of Gallium}=\frac{\text{Moles of electrons}}{n}$

where,

n = number of electrons transferred = 3

Putting values in above equation, we get:

$\text{Moles of Gallium}=\frac{1.52\times 10^{-3}}{3}=5.077\times 10^{-4}mol$

To calculate the mass of gallium, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$

Moles of Gallium = $5.077\times 10^{-4}mol$

Molar mass of Gallium = 69.72 g/mol

Putting values in above equation, we get:

$5.077\times 10^{-4}mol=\frac{\text{Mass of Gallium}}{69.72g/mol}\\\\\text{Mass of Gallium}=0.0354g$

Hence, the mass of gallium produced by the electrolysis is 0.0354 grams.

8 0

3 years ago

Which of the following are found outside the nucleus?

lora16 [44]

Answer:
electrons
Reason:
neutrons and protons are inside the nucleus

4 0

3 years ago

Read 2 more answers

Which of the following is not true about limiting and excess reagents?

Bogdan [553]

Answer : The incorrect option is, (d) The reactant that was the smallest given mass is the limiting reagent.

Explanation :

Limiting reagent : It is the reagent that is completely consumed in the chemical reaction when the chemical reaction is complete. No amount is left after the reaction is complete. The amount of product obtained is determined by the limiting reagent. A balanced equation is necessary to determine which reactant is limiting reagent.

Excess reagent : It is the reagent that are not completely consumed in the chemical reaction. That means the reagent is in excess amount. Some amount of the excess reagent is left over after the reaction is complete.

From this we conclude that the options, A, B and C are correct. While the option D is incorrect.

Option D is incorrect because it is not necessary the reactant that was the smallest given mass is the limiting reagent but it is judge by the number of moles present in the reaction.

Hence, the incorrect option is, (d)

4 0

3 years ago