How many molecules are in 3.23 moles of Silicon dioxide? (SiO2)

22. A flask containing 450 mL of 0.50 M H2SO4 was accidentally knocked to the floor. How many grams of NaHCO, do you need to put

Dvinal [7]

<u>Answer:</u> The correct answer is Option D.

<u>Explanation:</u>

To calculate the moles of a solute, we use the equation:

$\text{Molarity of the solution}=\frac{\text{Moles of solute}}\text{Volume of solution (in L)}}$

We are given:

Volume of sulfuric acid = 450mL = 0.45 L (Conversion factor: 1 L = 1000 mL)

Molarity of the solution = 0.5 moles/ L

Putting values in above equation, we get:

$0.5mol/L=\frac{\text{Moles of sulfuric acid}}{0.45L}\\\\\text{Moles of sulfuric acid}=0.225mol$

For the given chemical reaction:

$H_2SO_4(aq.)+2NaHCO_3(aq.)\rightarrow Na_2SO_4(aq.)+2H_2O(l)+2CO_2(g)$

By Stoichiometry of the reaction:

1 mole of sulfuric acid reacts with 2 moles of sodium bicarbonate.

So, 0.225 moles of sulfuric acid will react with = $\frac{2}{1}\times 0.225=0.45mol$ of sodium bicarbonate

To calculate the mass of sodium bicarbonate, we use the equation:

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

Moles of sodium bicarbonate = 0.45 moles

Molar mass of sodium bicarbonate = 84.007 g/mol

Putting values in above equation, we get:

$0.45mol=\frac{\text{Mass of sodium bicarbonate}}{84.007g/mol}\\\\\text{Mass of sodium bicarbonate}=38g$

Hence, the correct answer is Option D.

7 0

3 years ago

You are asked to write observations about a 100g sample of Nitrogen-16 before it decays, but you're running late. In order to ma

san4es73 [151]

Answer:

You cannot make observations if you are 57 seconds late into the lab.

Explanation:

The atomic nucleus can split by decay into 2 or more particles as a result of the instability of its atomic nucleus due to the fact that radioactive elements possess an unstable atomic nucleus.

Now, the primary particles which are emitted by radioactive elements in order to make them decay are alpha, beta & gamma particles.

The half life equation is;

N_t = N₀(½)^(t/t_½)

Where:

t = duration of decay

t_½ = half-life

N₀ = number of radioactive atoms initially

N_t = number of radioactive atoms remaining after decay over time t

We are given;

t = 57 secs

N₀ = 100 g

Now, half life of Nitrogen-16 from online sources is 7.2 seconds. t_½ = 7.2

Thus;

N_t = 100(1/2)^(57/7.2)

N_t = 0.4139g

We are told that In order to make observations, you require at least .5g of material.

The value of N_t you got is less than 0.5g, therefore you cannot make observations if you are 57 seconds late.

5 0

3 years ago

Determine what type of compound is shown below:

34kurt

Answer:

Polar

Explanation:

Methanol is not electrostatic

It's not metallic as it has no metals in it

It's not ionic as coordinate bonding is made.

It's polar as a lone pair is present over OH-

3 0

2 years ago

What are the strengths, weaknesses, and implications of the precautionary principle as a method for deciding whether a technolog

Brilliant_brown [7]

Answer:

The precautionary principle would prevent the implementation of technologies that possess a risk to humans, animals, and the environment. The strengths are that it will definately save the population and planet from a new technology that could cause long-term harm.

The weakness is that this principle may inhibit new technologies that are needed to help under-developed countries from preventing diseases. The precautionary principle states that technologies should entirely risk-free.

Explanation:

6 0

3 years ago

How does mass defect relate to binding energy in the nucleus?

Inessa [10]

Answer : B

Explanation : Just did it

8 0

3 years ago