Samantha & Ryan are investigating an unknown substance. They make the following observations about the substance: 1. it is b

Answer: The change in enthalpy for each mole of zinc involved in the reaction is 152.4 kJ/mol.

Explanation:

First, we need to determine the moles of Zn and HCl.

The molar mass of Zn is 65 g/mole

and,

Next, we must identify the limiting reagent and the excess reagent.

The chemical reaction given is:

According to the balanced reaction we find that

1 mole of reacts with 2 moles of

Thus, 0.0206 moles of react with moles of

This leads us to determine that is the excess reagent because the moles provided exceed the required moles, while is limiting and restricts product formation.

Now to find the enthalpy change for each mole of zinc reacting in this reaction.

From the reaction we gather that,[ [TAG_59]]

0.0206 moles of Zn yield heat = 3.14 kJ

This implies that 1 mole of Zn generates heat =

Hence, the enthalpy change per mole of zinc involved in this reaction amounts to 152.4 kJ/mol.

Cu(NO3)2 --> MM187.5558 NiNO3 *COEF2* --> 120.6983

The reaction can be described as follows: CO + 2H2 = CH3OH. Given the specified quantities of the reactants, we will identify the limiting reactant and compute the remaining excess amount. Calculating, 1.50 x 10^-6 g CO converts to 5.36 x 10^-8 mol CO, while 6.80 x 10^-6 g H2 equals 3.37 x 10^-6 mol H2. Thus, CO is fully consumed in the reaction, leaving 3.37 x 10^-6 - 5.36 x 10^-8 = 3.32 x 10^-6 moles of gas.

Greetings,

The number of lone pairs of electrons in a C2O molecule is...

4

Each Oxygen atom forms two bonds with Carbon.

I hope this was useful!

-Char

The answer is - 0.138 M. The buffer pH can be determined using the Henderson equation. Here, acts as a weak acid and serves as its corresponding conjugate base. The weak acid has two protons, while the base contains one. The equation can therefore be expressed in terms of protons transferred. Phosphoric acid can donate protons in three stages; the equation we’ve referenced pertains to the second stage, as the acid then has only two protons available and the base only one. Given the concentration of the acid as 0.10 M, we need to calculate the concentration of the base necessary to form a buffer with a pH of exactly 7.0. Substituting the values into the equation leads us to the solution. Cross-multiplying, we find that [base] = 1.38(0.10), yielding [base] = 0.138. Therefore, the concentration of the base needed for the buffer is 0.138 M.