Answer:- The substance is Propane and right choice is C.
Solution:- 10140000 J of heat is used to boil 28.47 kg at 298 K. Here, the important thing is, the liquid is changing to vapor and the temperature is not changing means it's a phase change. So, the formula used for this is:
where, q is the heat energy, m is mass and is the enthalpy of vaporization.
Let's rearrange the formula for as:
=
Let's plug in the values:
=
=
If we round this then it is . Hence, the right choice is C. propane.
Answer:
HNO₂ ⇄ H⁺ + NO₂⁻
Ka = 4.0 × 10⁻⁴
Explanation:
Step 1: Given data
- Concentration of nitrous acid (Ca): 0.010 M
Step 2: Write the acid dissociation reaction
Nitrous acid is a weak acid that dissociates according to the following expression.
HNO₂ ⇄ H⁺ + NO₂⁻
Step 3: Calculate the concentration of H⁺
We will use the definition of pH.
pH = -log [H⁺]
[H⁺] = antilog - pH = antilog -2.70 = 2.00 × 10⁻³ M
Step 4: Calculate the acid dissociation constant (Ka)
For a weak acid, we can calculate Ka using the following expression.
Ka = [H⁺]²/Ca
Ka = (2.00 × 10⁻³)²/0.010
Ka = 4.0 × 10⁻⁴
Answer:
Binomial Naming System
Explanation:
He was the first to use the system, he used it frequently enough for the system to be accepted and used more often by scientists. He believed that species were unable to be changed.