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3 years ago

Please Help with what you can and try 8 if possible

Chemistry

1 answer:

Ganezh [65]3 years ago

3 0

<span>The sun's gravitational pull keeps our planet orbiting the Sun. the moons gravity pulls on the earth and makes tides rise and fall every day</span>

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Exactly 1.0 mol N2O4 is placed in an empty 1.0-L container and is allowed to reach equilibrium described by the equation N2O4(g)

Tresset [83]

Answer : The equilibrium constant $K_c$ for the reaction is, 0.869

Explanation :

First we have to calculate the concentration of $N_2O_4$ .

$\text{Concentration of }N_2O_4=\frac{\text{Moles of }N_2O_4}{\text{Volume of solution}}$

$\text{Concentration of }N_2O_4=\frac{1.0moles}{1.0L}=1.0M$

The balanced equilibrium reaction is,

$N_2O_4(g)\rightleftharpoons 2NO_2(g)$

Initial conc. C 0

At eqm. conc. $(C-C\alpha)$ $(2C\alpha)$

As we are given,

The percent of dissociation = $\alpha$ = 37 % = 0.37

Now we have to calculate the equilibrium constant for the reaction.

The expression of equilibrium constant for the reaction will be :

$K_c=\frac{[NO_2]^2}{[N_2O_4]}$

$K_c=\frac{(2C\alpha)^2}{(C-C\alpha)}$

Now put all the values in this expression, we get :

$K_c=\frac{(2\times 1.0\times 0.37)^2}{(1.0-1.0\times 0.37)}$

$K_c=0.869$

Therefore, the equilibrium constant $K_c$ for the reaction is, 0.869

3 0

3 years ago

Find the mass in 2.6 mol of lithium bromide. (Hint: You need to write the formula)

marissa [1.9K]

Lithium Bromide : LiBr.

Molar mass of lithium bromide : 86.845 g/mol.

To find the mass of 2.6 mol of lithium bromide, simply multiply in order to cancel out the moles : 2.6 mol * 86.845 g / 1 mol = 225.8 grams.

6 0

3 years ago

3. When did Rachel Carson begin to see ominous signs of poisons in the environment?

RSB [31]

Answer: Rachel Carson was a brilliant woman who after following her dreams to become a scientist, even though many people warned her of her inevitable failure, wrote the book Silent Spring that changed the way the world view environmental safety.

Explanation:

8 0

4 years ago

II. Ionic Equations

mario62 [17]

Answer:

Complete ionic: $\begin{aligned}& \rm 2\, Ag^{+}\, (aq) + 2\, {NO_3}^{-} \, (aq) + Ca^{2+}\, (aq) + 2\, Cl^{-}\, (aq) \\ & \rm \to 2\, AgCl\, (s) + Ca^{2+}\, (aq) + 2\, {NO_3}^{-}\, (aq)\end{aligned}$ .

Net ionic: $\begin{aligned}& \rm Ag^{+}\, (aq) + Cl^{-}\, (aq) \to AgCl\, (s)\end{aligned}$ .

Explanation:

Start by identifying species that exist as ions. In general, such species include:

Soluble salts.
Strong acids and strong bases.

All four species in this particular question are salts. However, only three of them are generally soluble in water: $\rm AgNO_3$ , $\rm CaCl_2$ , and $\rm Ca(NO_3)_2$ . These three salts will exist as ions:

Each $\rm AgNO_3\, (aq)$ formula unit will exist as one $\rm Ag^{+}$ ion and one $\rm {NO_3}^{-}$ ion.
Each $\rm CaCl_2$ formula unit will exist as one $\rm Ca^{2+}$ ion and two $\rm Cl^{-}$ ions (note the subscript in the formula $\rm CaCl_2\!$ .)
Each $\rm Ca(NO_3)_2$ formula unit will exist as one $\rm Ca^{2+}$ and two $\rm {NO_3}^{-}$ ions.

On the other hand, $\rm AgCl$ is generally insoluble in water. This salt will not form ions.

Rewrite the original chemical equation to get the corresponding ionic equation. In this question, rewrite $\rm AgNO_3$ , $\rm CaCl_2$ , and $\rm Ca(NO_3)_2$ (three soluble salts) as the corresponding ions.

Pay attention to the coefficient of each species. For example, indeed each $\rm AgNO_3\, (aq)$ formula unit will exist as only one $\rm Ag^{+}$ ion and one $\rm {NO_3}^{-}$ ion. However, because the coefficient of $\rm AgNO_3\, (aq)\!$ in the original equation is two, $\!\rm AgNO_3\, (aq)$ alone should correspond to two $\rm Ag^{+}\!$ ions and two $\rm {NO_3}^{-}\!$ ions.

Do not rewrite the salt $\rm AgCl$ because it is insoluble.

$\begin{aligned}& \rm 2\, Ag^{+}\, (aq) + 2\, {NO_3}^{-} \, (aq) + Ca^{2+}\, (aq) + 2\, Cl^{-}\, (aq) \\ & \rm \to 2\, AgCl\, (s) + Ca^{2+}\, (aq) + 2\, {NO_3}^{-}\, (aq)\end{aligned}$ .

Eliminate ions that are present on both sides of this ionic equation. In this question, such ions include one unit of $\rm Ca^{2+}$ and two units of $\rm {NO_3}^{-}$ . Doing so will give:

$\begin{aligned}& \rm 2\, Ag^{+}\, (aq) + 2\, Cl^{-}\, (aq) \to 2\, AgCl\, (s)\end{aligned}$ .

Simplify the coefficients:

$\begin{aligned}& \rm Ag^{+}\, (aq) + Cl^{-}\, (aq) \to AgCl\, (s)\end{aligned}$ .

7 0

3 years ago

Hi someone help me pls

MAVERICK [17]

Answer:

Explanation:

chemical change results from a chemical reaction where nothing is change example of chemical changes burning, cooking, rotting and rusting

3 0

3 years ago

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