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3 years ago

How does a chemist count the number of particles in a given number of moles of a substance?

1 answer:

8 0

The chemist the count the number of particles (Atoms, Molecules or Formula Unit) in a given number of moles of a substance by using following relationship.

Moles = # of Particles / 6.022 × 10²³

Or,

# of Particles = Moles × 6.022 × 10²³

So, from above relation it is found that 1 mole of any substance contains exactly 6.022 × 10²³ particles. Greater the number of moles greater will be the number of particles.

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What is the concentration (m) of ch3oh in a solution prepared by dissolving 12.9 g of ch3oh in sufficient water to give exactly

Alexxandr [17]

Concentration (m) signify 'molality'

Concentration (M) signify 'Molarity'

Formula for molality (m) = $\frac{Moles of solute}{Mass of solvent in Kg}$

In the question denisty of solute is not given so we can calculate concentration (M) that is 'Molarity'

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

Moles of solute CH3OH = Given grams / Molar mass of CH3OH

Given grams of CH3OH = 12.9 g and molar mass = 32.0 g/mol

Moles of solute CH3OH = $12.9 g\times \frac{1mol}{32.0g}$

Moles of solute CH3OH = 0.403 mol

Volume of solution = 230 mL , we need to convert 230 mL to 'L'

Volume = $230 mL\times \frac{1 L}{1000 mL}$

Volume = 0.23 L

Molarity (M) = $\frac{0.403mol}{0.23L}$

Concentration (M) = 1.75 mol / L or 1.75 M

5 0

3 years ago

What is the IUPAC name of the following compound?

vaieri [72.5K]

Answer:

2,2,3-trimethylbutane

Step-by-step explanation:

Here are the rules for naming alkanes.

1. Find the longest continuous chain of carbon atoms.

There is a four-carbon chain (blue).

2. Name the main chain.

The chain has four C atoms, so its base name is butane.

3. Identify and name all the substituents.

There are three CH₃ groups (methyl, blue bonds).

4. Number the main chain from the end that gives the lowest possible locants to the substituents.

From the left-hand end, the locants are 2,2,3. From the right-hand end, they are 2,3,3. The first point of difference is the second locant. 2 < 3, so we number from the left.

5. Put the names of the substituents with their locants in alphabetical order in front of the base name with no spaces.

Use numbers to connect numbers and hyphens to connect numbers and letters.

The IUPAC name is 2,2,3-trimethylbutane.

4 0

3 years ago

What are three a ways orchids attract insects to spread their flower pollen

Licemer1 [7]

Orchids attract insects many different ways depending on the insect that they attract. Orchids attract flies by using the smell of rotten flesh. Gross right? Anyways another way they can attract insects is because of the shape of their petals. Some males insects think that their petals look like female insects and the male insect then lands on the petal and spreads pollen onto the flower Hope this helped - Ashlynn

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3 years ago

Which would be the best material to use for making tea kettles?

Wewaii [24]

It’s a subjective answer but glass is believed to be the most safe material to use for tea kettles

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3 years ago

Suppose that in an equilibrium mixture of HCl, Cl2, and H2, the concentration of H2 is 1.0 x 10-11 mol-L-1and that of Cl2 is 2.0

bekas [8.4K]

Considering the definition of Kc, the equilibrium molar concentration of HCl at 500 K is 0.0894 $\frac{mol}{L}$ .

The balanced reaction is:

H₂(g) +Cl₂(g) ⇆ 2 HCl(g)

Equilibrium is a state of a reactant system in which no changes are observed as time passes, despite the fact that the substances present continue to react with each other. In other words, reactants become products and products become reactants and they do so at the same rate.

In other words, chemical equilibrium is established when there are two opposite reactions that take place simultaneously at the same speed.

The concentration of reactants and products at equilibrium is related by the equilibrium constant Kc. Its value in a chemical reaction depends on the temperature and the expression of a generic reaction aA + bB ⇄ cC is

$K_{c} =\frac{[C]^{c} x[D]^{d} }{[A]^{a} x[B]^{b} }$

That is, the constant Kc is equal to the multiplication of the concentrations of the products raised to their stoichiometric coefficients by the multiplication of the concentrations of the reactants also raised to their stoichiometric coefficients.

In this case, the constant Kc can be expressed as:

$K_{c} =\frac{[HCl]^{2} }{[H_{2} ]x[Cl_{2} ] }$