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2 years ago

Please help me with my regents practice :((

Chemistry

1 answer:

BlackZzzverrR [31]2 years ago

8 0

Answer: 3 & 4

Explanation:

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If 5 moles of P4 reacted with 22 moles Cl2 according to the above reaction, determine:

GaryK [48]

Solution:

$P_4+6Cl_2\rightarrow 4PCl_3$

a) By stoichoimetry If 6 moles of $Cl_2$ gives 4 mole of $PCl_3$ , then 22 moles of $Cl_2$ will give: $\frac{4}{6}\times 22=\frac{44}{3}=14.66$ moles of $PCl_3$

b) If 6 moles of $Cl_2$ reacts with one mole of $P_4$ , then 22 moles of $Cl_2$ will react : $\frac{1}{6}\times 22=\frac{11}{3}=3.66$ moles of $P_4$

Moles of $P_4$ left after the reaction = $5-3.66=\frac{4}{3}=1.34$ moles.

c) 0 Moles of $Cl_2$ , since it is present in less amount it will get completely consumed in the reaction. Hence, it is limiting reagent.

7 0

2 years ago

The electron configuration of an element is 1s22s22p63s1 Describe what most likely happens when an atom of this element comes ne

trasher [3.6K]

Answer:

They will create an ionic bond.

Explanation:

The atom with the one valence electron will lose its one, because it's a metal and metals will lose electrons to become stable. The nonmetal (with 7 valence electrons) will gain that electron, therefore creating a stable octet for the nonmetal, making the compound stable.

3 0

1 year ago

Suppose you have just added 100 ml of a solution containing 0.5 mol of acetic acid per liter to 400 ml of 0.5 m naoh. what is th

Tpy6a [65]

$pH = 13.5$

Explanation:

Sodium hydroxide completely ionizes in water to produce sodium ions and hydroxide ions. Hydroxide ions are in excess and neutralize all acetic acid added by the following ionic equation:

$\text{HAc} + \text{OH}^{-} \to \text{Ac}^{-} + \text{H}_2\text{O}$

The mixture would contain

$0.4 \times 0.5 - 0.1 \times 0.5 = 0.15 \; \text{mol}$ of $\text{OH}^{-}$ and
$0.1 \times 0.5 = 0.05 \; \text{mol}$ of $\text{Ac}^{-}$

if $\text{Ac}^{-}$ undergoes no hydrolysis; the solution is of volume $0.1 + 0.4 = 0.5 \; \text{L}$ after the mixing. The two species would thus be of concentration $0.30 \; \text{mol} \cdot \text{L}^{-1}$ and $0.10 \; \text{mol} \cdot \text{L}^{-1}$ , respectively.

Construct a RICE table for the hydrolysis of $\text{Ac}^{-}$ under a basic aqueous environment (with a negligible hydronium concentration.)

$\begin{array}{cccccccc} \text{R} & \text{Ac}^{-}(aq) &+ & \text{H}_2\text{O}(aq) & \leftrightharpoons & \text{HAc}(aq) & + & \text{OH}^{-} (aq)\\ \text{I} & 0.10 \; \text{M} & & & & & &0.30 \; \text{M}\\ \text{C} & -x \; \text{M}& & & & +x \; \text{M}& & +x \; \text{M} \\ \text{E} & (0.10 - x) \; \text{M} & & & & x \; \text{M} & & (0.30 +x) \; \text{M} \end{array}$

The question supplied the <em>acid</em> dissociation constant $pK_a$ for acetic acid $\text{HAc}$ ; however, calculating the hydrolysis equilibrium taking place in this basic mixture requires the <em>base</em> dissociation constant $pK_b$ for its conjugate base, $\text{Ac}^{-}$ . The following relationship relates the two quantities:

$pK_{b} (\text{Ac}^{-}) = pK_{w} - pK_{a}( \text{HAc})$

... where the water self-ionization constant $pK_w \approx 14$ under standard conditions. Thus $pK_{b} (\text{Ac}^{-}) = 14 - 4.7 = 9.3$ . By the definition of $pK_b$ :

$[\text{HAc} (aq)] \cdot [\text{OH}^{-} (aq)] / [\text{Ac}^{-} (aq) ] = K_b = 10^{-pK_{b}}$

$x \cdot (0.3 + x) / (0.1 - x) = 10^{-9.3}$

$x = 1.67 \times 10^{-10} \; \text{M} \approx 0 \; \text{M}$

$[\text{OH}^{-}] = 0.30 +x \approx 0.30 \; \text{M}$

$pH = pK_{w} - pOH = 14 + \text{log}_{10}[\text{OH}^{-}] = 14 + \text{log}_{10}{0.30} = 13.5$

6 0

2 years ago

The value of Henry's law constant for oxygen in water at 242C is 1.66 x 1 ox M/torr. b. c. Calculate the solubility of oxygen in

DochEvi [55]

25ca an the oxygen gas is 2 atom ur mum

4 0

2 years ago

Which of the following statements about enthalpy is true?

Evgesh-ka [11]

Answer: A chemical process must occur and then changes between the state of the reactants and the state of the products can be determined

Explanation: Enthalpy represents the sum of the energy of the system with the product of the pressure and volume of that system. As a thermodynamic property, it expresses the ability to release heat from the system. In fact, enthalpy tells us how much heat and work has changed during the chemical reaction under constant pressure. When measuring, measurements of the difference in enthalpy between the two states of the system is performed, before and after the chemical reaction, since total enthalpy can not be measured. This measurement of the enthalpy change can tell us, for example, whether the heat was released from the system during the reaction, or the system absorbed the heat.

7 0

2 years ago