Aluminium is the most common metal in the Earth's crust.<br> Which is NOT a property of aluminium?

Use the standard reaction enthalpies given below to determine ΔH°rxn for the following reactionP4(g) + 10 Cl2(g) → 4PCl5(s) ΔH°r

weqwewe [10]

Answer:

Therefore $\bigtriangledown H^\circ_{rxn}$ = -1835 KJ

Explanation:

Enthalpy is denoted by H.

Enthalpy: Total heat change in a chemical reaction is called enthalpy.

The change of entalpy of a reaction is denoted by $\bigtriangledown H^\circ_{rxn}$

Hass's Law:The change in enthalpy of any process can be determined by calculating the sum of change in enthalpy of each of the steps involved in the process.

g= gas

S= solid

P₄(g)+10Cl₂(g)→ 4Cl₅(s) $\bigtriangledown H^\circ_{rxn}$ =?

PCl₅(s)→ PCl₃(g)+Cl₂(g) .......(1) $\bigtriangledown H^\circ_{rxn}$ = +157KJ

P₄(g)+6Cl₂(g)→ 4PCl₃(g).............(2) $\bigtriangledown H^\circ_{rxn}$ = -1207 KJ

If we flip a reaction the value of enthalpy will be change positive to negative or nagative to positive but the numerical value will be remain same.

We need rearrange the equation (1) because in the required equation Cl₂ is on the left side. So we flip the first equation.

PCl₃(g)+Cl₂(g)→PCl₅(s)......(3) $\bigtriangledown H^\circ_{rxn}$ = -157KJ

Multiplying 4 with equation (3)

4 PCl₃(g)+4Cl₂(g)→4PCl₅(s)......(4) $\bigtriangledown H^\circ_{rxn}$ =4×( -157)KJ= -628 KJ

Adding equation (2) and (4) we get

P₄(g)+6Cl₂(g)+4 PCl₃(g)+4Cl₂(g)→4PCl₃(g)+4PCl₅(s) $\bigtriangledown H^\circ_{rxn}$ =( -1207-628)KJ

⇒P₄(g)+10Cl₂(g)→4PCl₃(g)-4PCl₃(g)+4PCl₅(s) $\bigtriangledown H^\circ_{rxn}$ = - 1835KJ

⇒P₄(g)+10Cl₂(g)→ 4Cl₅(s) $\bigtriangledown H^\circ_{rxn}$ = -1835 KJ

Therefore $\bigtriangledown H^\circ_{rxn}$ = -1835 KJ

5 0

3 years ago

-FeS2+-O2->-Fe2O3+-SO2 What coefficient should be placed in front of SO2 to balance the equation?

NISA [10]

Answer:

8 should be placed in front of SO₂.

Explanation:

The easiest way to solve this question is by writing the <u>entire</u> balanced equation:

4FeS₂ + 11O₂ -> 2Fe₂O₃ + 8SO₂

We can achieve this by first balancing the Fe, then S, and finally the O.

We can also double check our answer by counting the number of each element on both sides:

-Reactants: 4 Fe, 8 S, 22 O

-Products: 4 Fe 8 S, 22 O

Since they match, our equation is balanced, and the coefficient in front of SO₂ is 8.

8 0

3 years ago

Three examples why cell division is important

kifflom [539]

Answer:

Cell division is important for growth,maintenance of proper chromosome number,wound healing

Explanation:

1 Cell division results in the formation of new cells which further undergo division to form new cells and so forth.Thus many cells are formed which are organized in tissues.Tissues then builds up organs and a number of organs builds up total body.

2 Cell division helps to maintain its chromosome number within the newly formed daughter cells.

3 Division of cells result in the formation of new cells in the site of wound and this accumalation of new cells in the wound region replace damaged and dead cells thus ultimately results in wound healing.

3 0

3 years ago

28 Which compound yields H + ions as the only positive ions in an aqueous solution?

MrMuchimi

Answer: (4) $CH_3COOH$

Explanation:-

According to Arrhenius concept, a base is defined as a substance which donates hydroxide ions $(OH^-)$ when dissolved in water and an acid is defined as a substance which donates hydronium ions $(H_3O^+)$ in water.