Pure substances and solutions are alike because they:

In the reaction, Zn(s) + 2 HCl(aq) --> ZnCl2 (aq)+ H2(g), 25 grams of Zn are reacted with 17.5 g of HCl. How many grams of H2

Gennadij [26K]

Answer:

0.480 g of H₂ are produced, in the reaction.

Explanation:

This is the reaction:

Zn(s) + 2HCl → ZnCl₂ (aq) + H₂ (g)

We havethe mass of both reactants, so we must work with them to find out the limiting reactant and then, determine the amount of H₂ produced.

Let's convert the mass to moles ( mass / molar mass)

25 g / 65.41 g/mol = 0.382 moles Zn

17.5 g / 36.45 g/mol = 0.480 moles HCl

Ratio is 1:2, so 1 mol of Zn react with the double of moles of HCl.

0.382 moles of Zn would need the double of moles to react, so (0.382 .2) = 0.764 moles of HCl. → We only have 0.480 moles, so the acid is the limiting.

Now let's determine the moles of H₂ formed.

Ratio is 2:1, so If i take account the moles I have, I will produce the half of moles of my product.

0.480 moles / 2 = 0.240 moles of H₂ are produced.

To find out the mass, we must multiply mol . molar mass

0.240 mol . 2g/mol = 0.480 g

3 0

3 years ago

Sodium burns violet in a flame. What is the energy of this blue light if a photon released has a wavelength of 413nm

ludmilkaskok [199]

According to Einstein the energy of photon is given by the equation,

E = hν = h . c/λ

where h is Planck's constant, c is the speed of light, ν is the frequency of light and λ is the wavelength of light.

Given, wavelength of photon = 413 nm = 413 x 10⁻⁹ m

Conversion factor: 1 nm = 10⁻⁹ m

c = 3 x 10⁸ m/s

h = 6.626× 10⁻³⁴ J.s

Substituting the data into the equation we get,

E = h . c/λ

E = 6.626× 10⁻³⁴ J.s x (3 x 10⁸ m/s) / 413 x 10⁻⁹ m

E = 4.8 x 10⁻¹⁹ J

The energy of this blue light is 4.8 x 10⁻¹⁹ J

7 0

4 years ago

There are many lewis structures you could draw for sulfuric acid, h2so4 (each h is bonded to an o). part a what lewis structure(

erica [24]

Structure 1 is satisfying octet rule because each atom surrounded by 8 electrons:
The valance electron for oxygen is 6, for sulfur is 6, but for hydrogen is 1. Therefore, the molecule has valance electrons. Sulfur is bonded with 4 oxygen atoms, 4 single bonds, whereas 2 hydrogen atoms are bonded with 2 oxygen atoms.

But the actual structure is 2 but it violates octet rule since S is surrounded in this case with 12 electrons

7 0

3 years ago

Read 2 more answers

7 km is equal to: 700 m 0.7 m 7,000 m 70 m

Vitek1552 [10]

7000m is the answer as 1 km is 1000m ...so 7km multiplied by 1000m u get 7000 m...and always remember if u r converting a bigger unit to a smaller unit u multiply and if u r converting a smaller unit to a bigger unit u divide

3 0

4 years ago

Read 2 more answers

What is the mole fraction of potassium dichromate, K2Cr2O7, in a solution prepared from 24.42 g of potassium dichromate and 240.

Harrizon [31]

Answer:

$6.19\times 10^{-3}$ is the mole fraction of potassium dichromate.