How did oxygen come up to make 21% of the earth's present atmosphere?

For the quantum number lower case L = 0, how many possible values are there for the quantum number m subscript l?

liubo4ka [24]

Only 0 is possible for ml

6 0

3 years ago

(20 points) i) An absorption intensity of 1.00 (in arbitrary units) is observed for the maximum peak of the 1:2:1 triplet of the

laiz [17]

Answer:

Concentration of ethanol required = 48.476 M

Explanation:

Given that:

the absorption intensity = 1.00

Molarity of ethanol = 1M

NMR instrument used = 160 MHz

Temperature used = 300 K

The required concentration of ethanol can be determined as follows:

$= ( 1 \ M \times \dfrac{160\ MHz }{450 \ MHz}) \times \dfrac{300 \ K}{2.2\ K}$

$= ( 1 \ M \times 0.3555 ) \times136.36}$

= 48.476 M

5 0

3 years ago

How many grams of nicl2∙6h2o will be used to prepare a 0. 0350 m, 500. 0 ml of nicl2 solution?

marin [14]

The mass of NiCl₂•6HO₂ needed to prepare a 0.035 M 500 mL solution of NiCl₂•6HO₂ is 4.165 g

<h3>What is molarity? </h3>

This is defined as the mole of solute per unit litre of solution. Mathematically, it can be expressed as:

Molarity = mole / Volume

<h3>How to determine the mole of NiCl₂•6HO₂</h3>

Molarity = 0.035 M
Volume = 500 mL = 500 / 1000 = 0.5 L

Mole of NiCl₂•6HO₂ =?

Mole = Molarity × Volume

Mole of NiCl₂•6HO₂ = 0.035 × 0.5

Mole of NiCl₂•6HO₂ = 0.0175 mole

<h3>How to determine the mass of NiCl₂•6HO₂</h3>

Mole of NiCl₂•6HO₂ = 0.0175 mole
Molar mass of NiCl₂•6HO₂ = 238 g/mol

Mass of NiCl₂•6HO₂ =?

Mass = mole × molar mass

Mass of NiCl₂•6HO₂ = 0.0175 × 238

Mass of NiCl₂•6HO₂ = 4.165 g

Thus, 4.165 g of NiCl₂•6HO₂ is needed to prepare the solution

Learn more about molarity:

brainly.com/question/15370276

3 0

2 years ago

Chlorine gas is added to a large flask to a pressure of 1.85 atm, at a temperature of 322 K. Phosphorus is added, and a reaction

AVprozaik [17]

Answer:

The volume of the flask is<u> 20.245 litres .</u>

Explanation:

We are given with following information-

$PV=nRT$ -------- 1

where R = $0.0821L.atom/mole.K$

Molar mass of $PCl_5=208.22g/mole$

The given chemical equation is -

$2P _(_s_)+5Cl_2 _(_g_)\rightarrow2PCl_5 _(_s_)$ --------- 2

Now , calculation -

Mass of $PCl_5$ formed = 118g

Molar mass of $PCl_5$ = $208.22g/mole$

Mole = $\frac{mass (g)}{molar mass}$

Therefore , moles of $PCl_5$ formed = $\frac{118}{208.22}$

From equation 2 , we get to know that ,

2mole $PCl_5$ formed from 5 mole $Cl_2 _(_g_)$

Therefore , $\frac{118}{208.22}$ mole $PCl_5$ formed from $\frac{5}{2} \times\frac{118}{208.22}$ mole $Cl_2 _(_g_)$

Moles of $Cl_2 _(_g_)$ used = $\frac{5\times118}{2\times208.22} mole$

R= $0.0821L.atom/mole.K$

Pressure (P)= 1.85atm

Temperature (T)= 322K

Moles of $Cl_2 _(_g_)$ (n)= $\frac{5}{2} \times\frac{118}{208.22}$ moles

Applying the formula above in 1 equation , that is

PV = nRT

putting the given values -

$1.85 \times V=\frac{5}{2} \times\frac{118}{208.22}\times0.0821\times322$

V = 20.245 litres.

Hence , the volume of the flask is <u>20.245 litres . </u>

8 0

3 years ago

What is the temperature when ice Melt

frez [133]

At temperatures above 32°F (0°C), pure water ice melts and changes state from a solid to a liquid (water); 32°F (0°C) is the melting point. For most substances, the melting and freezing points are about the same temperature.

Hope i didn't give you to much info that all the info about ice melting.

4 0

3 years ago