Which kingdom represents both multi & unicellular organisms? choose ONE.

Lighters are usually fueled by butane (c4h10). when 1 mole of butane burns at constant pressure, it produces 2658 kj of heat and

Leokris [45]

Answer:

ΔE = -2661 KJ/mole

ΔH = -2658 KJ/mole

Explanation:

ΔH = q - PΔV

ΔE = q + w

First, to find ΔE:

The reaction PRODUCES 2658 kJ of h (q), and does 3 kJ of work (w).

2658 kJ(q) + 3 kJ(w) = 2661 kJ, BUT the reaction PRODUCES heat, which means ΔE is negative.

ΔE = -2661 KJ/mole

Second, to find ΔH:

ΔH = q - PΔV

ΔH = 2658 kJ(q) - PΔV

Now, the question states that butane burns at a constant pressure; that just translates to the pressure of the reaction is equal to 0.

ΔH = 2658 KJ(q) - (0)ΔV

ΔH = 2658 KJ - 0

ΔH = 2658 kJ, BUT, like before, the reaction PRODUCES heat, which also mean ΔH is negative.

ΔH = -2658 KJ/mole

I hope this helped! Have a nice week.

5 0

4 years ago

A volume of 125 mL of H2O is initially at room temperature (22.00 ∘C). A chilled steel rod at 2.00 ∘C is placed in the water. If

inn [45]

Answer:

$m_{steel}=54.47gSteel$

Explanation:

Hello,

In this case, one considers that the heat lost by the water is gained by the steel rod:

$\Delta H_{water}=-\Delta H_{steel}$

That in terms of masses, heat capacities and temperatures is:

$m_{water}Cp_{water}(T_F-T_{water})=-m_{steel}Cp_{steel}(T_F-T_{steel})$

Thus, solving for the mass of the steel rod, we obtain:

$m_{steel}=\frac{m_{water}Cp_{water}(T_F-T_{water})}{-Cp_{steel}(T_F-T_{steel})} \\\\m_{steel}=\frac{125mL*\frac{1g}{1mL}*4.18\frac{J}{g^oC} (22.00^oC-21.10^oC)}{-0.452\frac{J}{g^oC}*(2.00^oC-21.10^oC)} \\\\m_{steel}=54.47gSteel$

Best regards.

6 0

4 years ago

Determine the formula of chromic acid.

Katyanochek1 [597]

Answer: The formula of chromic acid is $H_2CrO_4$

Explanation:

We are given an ionic compound named as chromic acid. This acid is formed by the combination of hydrogen ion and chromate ion.

An acid is defined as the substance which releases hydrogen ion when dissolved in water.

Hydrogen is the 1st element of periodic table having electronic configuration of $1s^1$ .

This element will loose 1 electron to form $H^{+}$ ion.

Chromate ion is a polyatomic ion having chemical formula of $CrO_4^{2-}$

By criss-cross method, the oxidation state of the ions gets exchanged and they form the subscripts of the other ions. This results in the formation of a neutral compound.

So, the chemical formula for the given compound is $H_2CrO_4$

Thus, the formula of chromic acid is $H_2CrO_4$

8 0

3 years ago

Why is sulphur more reactive than chlorine

Marina86 [1]

Answer:

Because the most reactive elements are HALOGENS.

4 0

3 years ago

Read 2 more answers

Calculate the number of molecules in 4.0 mol H2O.

Juliette [100K]

1 mole H2O ---------------------- 6.02x10²³ molecules
4 moles H2O--------------------- y molecules

y = 4 * 6.02x10²³

y = 2.4x10^24 molecules

answer b

hope this helps!.

7 0

3 years ago