A high school chemistry teacher needs to dilute her stock of

How many molecules are there in 4dm³ of nitrogen gas

daser333 [38]

There are 1.078 x 10²³ molecules

<h3>Further explanation</h3>

Given

4 dm³ = 4 L Nitrogen gas

Required

Number of molecules

Solution

Assumptions on STP (1 atm, 273 K), 1 mol gas = 22.4 L, so for 4 L :

mol = 4 : 22.4

mol = 0.179

1 mol = 6.02 x 10²³ particles(molecules, atoms)

For 0.179 :

= 0.179 x 6.02 x 10²³

= 1.078 x 10²³

5 0

2 years ago

If an experiment calls for 0.200mole acetic acid (Hc2H3O2)how many grams of glacial acetic acid do we need?

bija089 [108]

<h3>Molar mass:-</h3>

$\\ \sf\longmapsto HC_2H_3O_2$

$\\ \sf\longmapsto 1u+2(12u)+3(1u)+2(16u)$

$\\ \sf\longmapsto 1u+24u+3u+48u$

$\\ \sf\longmapsto 28u+48u$

$\\ \sf\longmapsto 76u$

$\\ \sf\longmapsto 76g/mol$

No of moles=0.2mol
Given mass=?

$\\ \sf\longmapsto No\:of\;moles=\dfrac{Given\:Mass}{Molar\:Mass}$

$\\ \sf\longmapsto 0.2=\dfrac{Given\:mass}{76}$

$\\ \sf\longmapsto Given\:Mass=0.2\times 76$

$\\ \sf\longmapsto Given\:Mass=1.52g$

7 0

3 years ago

Chem help<br>calculate the wavelength of an electromagnetic wave with a frequency of (in pic)

olchik [2.2K]

we have,

wavelenght=c/f

where c= 3×10^8 m/s

f=6.3×10^12 s^-1

so wavelength=(3×10^8)/(6.3×10^12)

=0.476×10^-4 m

4 0

3 years ago

Write ionic equations for any three of the following:

worty [1.4K]

1.

The ionic equation is:

H⁺(aq) + NO₃⁻(aq) + Na⁺(aq) + OH⁻(aq) → Na⁺(aq) + NO₃⁻(aq) + H₂O(l)

HNO₃(aq) + NaOH(aq) → NaNO₃(aq) + H2O(l)

The required dissociations are

HNO₃(aq) → H⁺(aq) + NO₃⁻(aq)

NaOH(aq) → Na⁺(aq) + OH⁻(aq)

NaNO₃(aq) → Na⁺(aq) + NO₃⁻(aq)

So, the ionic equation is

H⁺(aq) + NO₃⁻(aq) + Na⁺(aq) + OH⁻(aq) → Na⁺(aq) + NO₃⁻(aq) + H₂O(l)

2.

The ionic equation is

H⁺(aq) + Cl⁻(aq) + K⁺(aq) + OH⁻(aq) → K⁺(aq) + Cl⁻(aq) + H₂O(l)

HCl(aq) + KOH(aq) → KCl(aq) + H2O(l)

The required dissociations are

HCl(aq) → H⁺(aq) + Cl⁻(aq)

KOH(aq) → K⁺(aq) + OH⁻(aq)

KCl(aq) → K⁺(aq) + Cl⁻(aq)

So, the ionic equation is

H⁺(aq) + Cl⁻(aq) + K⁺(aq) + OH⁻(aq) → K⁺(aq) + Cl⁻(aq) + H₂O(l)

3.

The ionic equation is

2H⁺(aq) + SO₄²⁻(aq) + Mg²⁺(aq) + 2OH⁻(aq) → Mg²⁺(aq) + SO₄²⁻(aq)

+ 2H₂O(l)

H₂SO₄(aq) + Mg(OH)₂(aq) → MgSO₄(aq) + 2H2O(l)

The required dissociations are

H₂SO₄(aq) → 2H⁺(aq) + SO₄²⁻(aq)

Mg(OH)₂(aq) → Mg²⁺(aq) + 2OH⁻(aq)

MgSO₄(aq) → Mg²⁺(aq) + SO₄²⁻(aq)

So, the ionic equation is

2H⁺(aq) + SO₄²⁻(aq) + Mg²⁺(aq) + 2OH⁻(aq) → Mg²⁺(aq) + SO₄²⁻(aq)

+ 2H₂O(l)

Learn more about ionic equations here:

brainly.com/question/11628165

5 0

2 years ago

How many moles of H2O are needed to produce 5.6 mol of NaOH?<br> Na2O + H2O --> 2NaOH

navik [9.2K]

Answer: 2.8 moles

Explanation:

The balanced equation below shows that 1 mole of sodium oxide reacts with 1 mole of water to form 2 moles of sodium hydroxide respectively.

Na2O + H2O --> 2NaOH

1 mole of H2O = 2 moles of NaOH

Let Z moles of H2O = 5.6 mole of NaOH

To get the value of Z, cross multiply

5.6 moles x 1 mole= Z x 2 moles

5.6 = 2Z

Divide both sides by 2

5.6/2 = 2Z/2

2.8 = Z

Thus, 2.8moles of H2O are needed to produce 5.6 mol of NaOH

3 0

3 years ago