1. Which two groups of elements in the periodic table are the most reactive?(1 point) A) alkali metals and halogens B) alkaline

Response:

Here's my calculation

Clarification:

Assume the starting concentrations of H₂ and I₂ are 0.030 and 0.015 mol·L⁻¹, respectively.

We need to determine the initial concentration of HI.

1. We will need a chemical equation with concentrations, so let's compile all the information in one location.

H₂ + I₂ ⇌ 2HI

I/mol·L⁻¹: 0.30 0.15 x

2. Calculate the concentration of HI

3. Plot the initial values

The graph below visualizes the initial concentrations as plotted on the vertical axis.

Clarification:

To obtain the specific element, you should multiply the grams provided by the ratio of grams of that particular element within its complete compound.

Since the query did not indicate the amount of NO2 produced, we can consider its mass to be negligible, thus assigning 1 mole to Nitrogen.

Correct answer:

C) Ca(OH)2

Note: The listed options in the question are incorrect. The accurate selections are shown below:

15. A total of 3.705 kg of substance Y is required to neutralize 100 moles of HCl(aq).

What might substance Y be? A Ca B CaO C Ca(OH)2 D CaCO3

Explanation:

A) Ca + 2HCl ---> CaCl2 + H2

Molar mass of Ca = 40 g/mol

The mass of Ca needed to neutralize 100 moles of HCl = 1/2 * 100 * 40 g = 2000g or 2 kg

B) CaO + 2HCl ---> CaCl2 + H2O

Molar mass of CaO = 56.1 g/mol

The mass of CaO needed to neutralize 100 moles of HCl = 1/2 * 100 * 56.1 g = 2805 g or 2.805 kg

C) Ca(OH)2 + 2HCl ---> CaCl2 + 2H2O

Molar mass of Ca(OH)2 = 74.1 g/mol

The mass of Ca(OH)2 necessary to neutralize 100 moles of HCl = 1/2 * 100 * 74.1 g = 3705 g or 3.705 kg

D) CaCO3 + 2HCl ---> CaCl2 + H2O + CO2

Molar mass of CaCO3 = 100 g/mol

The mass of CaCO3 required to neutralize 100 moles of HCl = 1/2 * 100 * 100 = 5000 g or 5.00 kg

Thus, the right choice is C.