Which answer would represent 0.001 moles?

A sample was prepared by mixing 18. ml of 3.00 x 10^-3 m crystal violet (cv) with 2.00 ml of 0.250 m naoh. calculate the resulti

Aleks [24]

Answer : The resulting concentrations of CV and NaOH are 0.0027 M and 0.025 M respectively.

Explanation :

Step 1 : Find moles of crystal violet and NaOH.

The molarity formula is

$Molarity = \frac{mol}{L}$

Molarity of crystal violet = $3.00 \times 10^{-3} = \frac{mol (CrystalViolet)}{L}$

The volume of crystal violet solution is 18 mL which is 0.018 L.

Moles of crystal violet = $3.00 \times 10^{-3} \times 0.018 = 5.4 \times 10^{-5}$

Moles of crystal violet = 5.4 x 10⁻⁵

Moles of NaOH = $Molarity \times L = 0.250 \times 0.00200 = 5.00 \times 10^{-4}$

Moles of NaOH = 5.00 x 10⁻⁴

Step 2 : Find total volume of the solution

The total volume of the solution after mixing NaOH and crystal violet is

0.018 L + 0.00200 = 0.020 L

Step 3 : Use molarity formula to find final concentrations

Molarity of crystal violet = $\frac{mol(CrystalViolet)}{Total Volume(L) } = \frac{5.4 \times 10^{-5}}{0.020} = 2.7 \times 10^{-3}$

Final concentration of CV = 0.0027 M

Molarity of NaOH= $\frac{mol(NaOH)}{Total Volume(L) } = \frac{5.00 \times 10^{-4}}{0.020} = 0.025 \times 10^{-3}$

NaOH is a strong base and dissociates completely as follows.

$NaOH (aq) \rightarrow Na^{+} (aq) + OH^{-} (aq)$

The mole ratio of NaOH and OH⁻ is 1:1 . Therefore the concentration of OH⁻ is same as that of NaOH.

Concentration of OH⁻ = 0.025 M

8 0

3 years ago

A mixture of pepper and water is a suspension because ________ HELPPPP

malfutka [58]

It doesn't because pepper does not dissolve

7 0

4 years ago

It took 4.5 minutes for 1.0 l helium to effuse through a porous barrier. how long will it take for 1.0 l cl2 gas to effuse under

serious [3.7K]

When The rate of effusion is inversely proportional to the √molar mass of the substance.
and we have R(He) = 1L / 4.5 min so,
R(He)/R(Cl2) = (molar mass of Cl2/ molar mass of He)^0.5
and when we have the molar mass of Cl2 = 70.9 & the molar mass of He = 4
so by substitution:
(1L/4.5 min)/ R(Cl2) = (70.9 / 4)^0.5
(1L/4.5 min) / R(Cl2) = 4.21
∴R(Cl2) = (1L/4.5 min) / 4.21 = 1L/ (4.5*4.21)min = 1 L / 18.945 min
∴Cl2 will take 18.945 min for 1 L to effuse under identical conditions

4 0

4 years ago

Ethane, C2H6, can be formed by reacting acetylene, C2H2, with hydrogen gas as follows: C2H2(g) H2(g) ⇌ C2H6(g) Exothermic What c

Pavel [41]

Answer:

Equilibrium shifts to the right

Explanation:

An exothermic reaction is one in which temperature is released to the environment. Hence, if the reaction vessel housing an exothermic reaction is touched after reaction completion, we will notice that the reaction vessel e.g beaker is hot.

To consider the equilibrium response to temperature changes, we need to consider if the reaction is exothermic or endothermic. In the case of this particular question, it has been established that the reaction is exothermic.

Heat is released to the surroundings as the reactants are at a higher energy level compared to the products. Hence, increasing the temperature will favor the formation of more reactants and as such, the equilibrium position will shift to the left to pave way for the formation of more reactants. Thus , more acetylene and hydrogen would be yielded

8 0

3 years ago

Lol can some have helo me out its easy <br> 1, 2 and 3

devlian [24]

Answer:

1. A

2. C

3. C

Explanation:

1. there are single cell organisms

2. all others are abiotic factors

3. individual is just one, population is one species, community is all populations, ecosystem includes abiotic and biotic factors, biome is a large geographical area.

3 0

3 years ago