Which of the following characterizes a reaction at equilibrium?

How does the law conservation of matter apply to machines

IRINA_888 [86]

The Law of Conservation of Matter says that the amount of matter stays the same, even when matter changes form. ... Another way to explain the law of conservation of matter is to say that things cannot be magically created or destroyed. Please mark brainliest?

5 0

3 years ago

A student performs an experiment to find the percentage of water in a hydrate. He determines that the hydrate contains 22% water

Stels [109]

Answer:

A feasible error could have been the removal of the sample before all water evaporated.

Explanation:

In order to determine the percentage of water in an hydrate, an experiment that could be performed is the heating of the sample until the mass does not change. If the student heated the sample an insufficient amount of time, water will be present in the sample, thus reducing the percentage reported.

4 0

3 years ago

s) Suppose we now collect hydrogen gas, H2(g), over water at 21◦C in a vessel with total pressure of 743 Torr. If the hydrogen g

Elenna [48]

This is an incomplete question, here is a complete question.

Suppose we now collect hydrogen gas, H₂(g), over water at 21°C in a vessel with total pressure of 743 Torr. If the hydrogen gas is produced by the reaction of aluminum with hydrochloric acid:

$2Al(s)+6HCl(aq)\rightarrow 2AlCl_3(aq)+3H_2(g)$

what volume of hydrogen gas will be collected if 1.35 g Al(s) reacts with excess HCl(aq)? Express your answer in liters.

Answer : The volume of hydrogen gas that will be collected is 1.85 L

Explanation :

First we have to calculate the number of moles of aluminium.

Given mass of aluminium = 1.35 g

Molar mass of aluminium = 27 g/mol

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

$\text{Moles of aluminium}=\frac{1.35g}{27g/mol}=0.05mol$

The given chemical reaction is:

$2Al(s)+6HCl(aq)\rightarrow 2AlCl_3(aq)+3H_2(g)$

As, hydrochloric acid is present in excess. So, it is considered as an excess reagent.

Thus, aluminium is a limiting reagent because it limits the formation of products.

By Stoichiometry of the reaction:

2 moles of aluminium produces 3 moles of hydrogen gas

So, 0.005 moles of aluminium will produce = $\frac{3}{2}\times 0.05=0.0750mol$ of hydrogen gas

Now we have to calculate the mass of helium gas by using ideal gas equation.

PV = nRT

where,

P = Pressure of hydrogen gas = 743 Torr

V = Volume of the helium gas = ?

n = number of moles of hydrogen gas = 0.075 mol

R = Gas constant = $62.364\text{ L Torr }mol^{-1}K^{-1}$

T = Temperature of hydrogen gas = $21^oC=[21+273]K=294K$

Now put all the given values in above equation, we get:

$743Torr\times V=0.075mol\times 62.364\text{ L Torr }mol^{-1}K^{-1}\times 294K\\\\V=1.85L$

Hence, the volume of hydrogen gas that will be collected is 1.85 L

8 0

3 years ago

Increasing the concentration of reactants generally increases the rate of a reaction because particles

Aleks [24]

This increases the rate of rxn because the particles, because according to the Collision Theory, the rate of rxn is proportional to number of effective collisions between the reactant molecules.

4 0

3 years ago

Why are yeast cells used in making bread?

tatiyna

Answer:

Yeast is used for the leavening of bread. Yeast uses the sugars and oxygen in dough to produce more yeast cells and carbon dioxide gas. The carbon dioxide makes the dough rise which gives the bread a light and spongy texture. Yeast also works on the gluten network.

Explanation:

5 0

2 years ago

Which of the following characterizes a reaction at equilibrium?​

Which of the following characterizes a reaction at equilibrium?