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3 years ago

Hurry plz

Chemistry

2 answers:

erik [133]3 years ago

4 0

Answer:

1) The correct step in the scientific method that Victor did is Construct a hypothesis.

2) Given mass and density, volume is calculated as mass divided by density.

Explanation:

1) Before doing the assay and make a graph with the results obtained, Victor should think what he wants to prove, so he should make a hypoythesis to test with the assay.

2) The formula of density is

density = mass/volume ⇒ density x volume = mass ⇒ volume = mass/density.

cricket20 [7]3 years ago

4 0

Answer:

construct a hypothesis

Explanation:

he was actually suppose to analyze the data before construct a hypothesis.

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When nitrogen dioxide (NO2) from car exhaust combines with water in the air, it forms nitric acid (HNO3), which causes acid rain

yKpoI14uk [10]

Answer:

For a: The number of molecules of nitrogen dioxide is $4.52\times 10^{23}$

For b: The mass of nitric acid formed is 54.81 grams

For c: The mass of nitric acid formed is 206 grams

Explanation:

The given chemical reaction follows:

$3NO_2(g)+H_2O(l)\rightarrow 2HNO_3(aq.)+NO(g)$

For a:

By Stoichiometry of the reaction:

1 mole of water reacts with 3 moles of nitrogen dioxide

So, 0.250 moles of water will react with $\frac{3}{1}\times 0.250=0.75mol$ of nitrogen dioxide

According to mole concept:

1 mole of a compound contains $6.022\times 10^{23}$ number of molecules.

So, 0.75 moles of nitrogen dioxide will contain $0.75\times 6.022\times 10^{23}=4.52\times 10^{23}$ number of molecules

Hence, the number of molecules of nitrogen dioxide is $4.52\times 10^{23}$

For b:

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

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$ .....(1)

Given mass of nitrogen dioxide = 60.0 g

Molar mass of nitrogen dioxide = 46 g/mol

Putting values in equation 1, we get:

$\text{Moles of nitrogen dioxide}=\frac{60.0g}{46g/mol}=1.304mol$

By Stoichiometry of the reaction:

3 moles of nitrogen dioxide produces 2 mole of nitric acid

So, 1.304 moles of nitrogen dioxide will produce = $\frac{2}{3}\times 1.304=0.870$ moles of nitric acid

Now, calculating the mass of nitric acid from equation 1, we get:

Molar mass of nitric acid = 63 g/mol

Moles of nitric acid = 0.870 moles

Putting values in equation 1, we get:

$0.870mol=\frac{\text{Mass of nitric acid}}{63g/mol}\\\\\text{Mass of nitric acid}=(0.870mol\times 63g/mol)=54.81g$

Hence, the mass of nitric acid formed is 54.81 grams

For c:

For nitrogen dioxide:

Given mass of nitrogen dioxide = 225 g

Molar mass of nitrogen dioxide = 46 g/mol

Putting values in equation 1, we get:

$\text{Moles of nitrogen dioxide}=\frac{225g}{46g/mol}=4.90mol$

For water:

Given mass of water = 55.2 g

Molar mass of water = 18 g/mol

Putting values in equation 1, we get:

$\text{Moles of water}=\frac{55.2g}{18g/mol}=3.06mol$

By Stoichiometry of the reaction:

3 moles of nitrogen dioxide reacts with 1 mole of water

So, 4.90 moles of nitrogen dioxide will react with = $\frac{1}{3}\times 4.90=1.63mol$ of water

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

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

By Stoichiometry of the reaction:

3 mole of nitrogen dioxide produces 2 moles of nitric acid

So, 4.90 moles of nitrogen dioxide will produce $\frac{2}{3}\times 4.90=3.27mol$ of nitric acid

Now, calculating the mass of nitric acid from equation 1, we get:

Molar mass of nitric acid = 63 g/mol

Moles of nitric acid = 3.27 moles

Putting values in equation 1, we get:

$3.27mol=\frac{\text{Mass of nitric acid}}{63g/mol}\\\\\text{Mass of nitric acid}=(3.27mol\times 63g/mol)=206g$

Hence, the mass of nitric acid formed is 206 grams

7 0

3 years ago

Which type of molecule is used by organisms to store and transmit genetic information?

Andre45 [30]

It’s RNA and DNA that stores and transmits genetic information

8 0

3 years ago

Read 2 more answers

Percent yield is the quantity of product actually produced compared to the quantity _______.

ss7ja [257]

Answer:

Of expected product

Explanation:

6 0

3 years ago

Im about to take first year chemistry for engineering. Should i review or will this be done in class? If yes what are some conce

sashaice [31]

You should always study. you can be above your class. thats what i do.. search google for ur course. they can tell u some key points for it. u should even study what you know and want to know as well.

6 0

3 years ago

9. In a period, do the number of shielding electrons change? Why do you think

Setler79 [48]

Answer:

The nuclear charge increases, but the number of inner shielding electrons stays the same.

Explanation:

Their shielding does not change, so the effective nuclear charge — the charge felt by a valence electron — increases.

The valence electrons are pulled closer to the nucleus, decreasing the atomic radius.

For example, consider the elements of Period 3.

$\begin{array}{ccccc}& & \textbf{Number of} & \textbf{Inner} & \textbf{Valence}\\\textbf{At. No.} & \textbf{Symbol} & \textbf{Protons} & \textbf{Electrons} & \textbf{Electrons}\\11& \text{Na} & 11 & 10 & 1\\12& \text{Mg} &12 & 10 & 2\\13& \text{Al} & 13 & 10 & 3 \\14& \text{Si} & 14 & 10 & 4 \\15& \text{P} & 15 & 10 & 5\\16& \text{S} & 16 & 10 & 6\\17& \text{Cl} & 17 & 10 & 7\\18& \text{Ar} & 18 & 10 & 8 \\\end{array}$

The number of protons increases as you go from one element to the next, but the number of inner electrons is constant.

3 0

3 years ago