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3 years ago

In chemical reactions, atoms are

1 answer:

5 0

<span>In chemical reaction, atoms always are rearranged. They are never destroyed or created because it would contradict the law of conservation of energy. The law of conservation of energy states that a matter cannot be created nor destroyed. It can only be formed in one way or the other. Also it cannot be neutralized. Resulting in one cannot be part of a chemical reaction. An example of this is the reaction HCl + NaOH -> NaCl + H2O. the reactants and products are not created, they are just formed into another substance.</span>

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When electrons flow steadily in one direction, the current is:

Sonbull [250]

The answer is direct

7 0

3 years ago

2CrO4 2−(aq)+2H+(aq)⇌Cr2O7 2−(aq)+H2O(l)Write the equation for the equilibrium constant (K) of the reaction studied in this exer

Vikki [24]

Answer:

$K = \frac {[Cr_{2}O_{7}^{2-}]}{[CrO_{4}^{2-}]^{2} \cdot [H_{3}O^{+}]^{2}}$

Explanation:

The equilibrium constant for a given reversible aqueous reaction is defined by the product ratio of the concentrations between the products and reactants:

aA + bB ⇄ cC + dD

$K = \frac {[products]^{p}}{[reactants]^{r}} = \frac {[C]^{c} \cdot [D]^{d}}{[A]^{a} \cdot [B]^{b}}$

<em>where K: is the equilibrium constant, [C] and [D]: are the product concentrations, [A] and [B]: are the reactant concentrations and a,b,c,d: are the stoichiometric coefficients from the reaction. </em>

Therefore, based on the definition the equilibrium constant of our reaction is:

2CrO₄²⁻(aq) + 2H₃O⁺(aq) ⇄ Cr₂O₇²⁻(aq) + 3H₂O(l)

$K = \frac {[Cr_{2}O_{7}^{2-}]}{[CrO_{4}^{2-}]^{2} \cdot [H_{3}O^{+}]^{2}}$

Generally, the water concentration is omitted from the expressions.

I hope it helps you!

8 0

3 years ago

A student dissolves 6.2g of aniline c6h5nh2 in 350.ml of a solvent with a density of 1.04/gml . the student notices that the vol

Troyanec [42]

Answer : The correct answer for molarity = 0.19 $\frac{mol}{L}$ and Molality = 0.18 $\frac{mol}{Kg}$ .

Given : Mass of aniline = 6.2 g

Volume of solvent = 350 mL Density of solvent = 1.04 g/mL

1) Molarity : It is defined as number of moles of solute present in Litre of solution . It is expressed as :

$Molarity(M) = \frac{moles of solute(mole)}{volume of solution (L)}$ \

Molairty can be found in following steps :

Step 1 : To calculate mole :

Mole of solute can be calculate using mole formula :

$Mole of solute = \frac{given mass of solute (g)}{molar mass of solute\frac{g}{1 mol}}$

Molar mass of aniline (C₆H₅NH₂) = 93.13 $\frac{g}{1 mol}$

Mass of aniline = 6.2 g

Plugging values in mole formula :

$Mole = \frac{6.2 g}{93.13 \frac{g}{1 mol}}$

Mole = 0.0665 mol

Step 2 : To find volume of solution

Volume of solution = volume of solute + volume of solution

Since addition of aniline does not change final volume , so volume of solvent = volume of solution. Since volume is given in mL , so it need to be converted to L .

1 L = 1000mL

$Volume of solution = \frac{350 mL}{1000mL} * 1 L$