1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
hammer [34]
3 years ago
7

When 21.45 g of KNO3 was dissolved in water in a calorimeter, the temperature fell from 25.00°C to 14.14 °C. If the heat capacit

y is 0.505KJ/°C, what will be the delta H for the solution process.
Chemistry
1 answer:
pashok25 [27]3 years ago
4 0

25.9 kJ/mol. (3 sig. fig. as in the heat capacity.)

<h3>Explanation</h3>

The process:

\text{KNO}_3\;(s) \to \text{KNO}_3\;(aq).

How many moles of this process?

Relative atomic mass from a modern periodic table:

  • K: 39.098;
  • N: 14.007;
  • O: 15.999.

Molar mass of \text{KNO}_3:

M(\text{KNO}_3) = 39.098 + 14.007 + 3\times 15.999 = 101.102\;\text{g}\cdot\text{mol}^{-1}.

Number of moles of the process = Number of moles of \text{KNO}_3 dissolved:

\displaystyle n = \frac{m}{M} = \frac{21.45}{101.102} = 0.212162\;\text{mol}.

What's the enthalpy change of this process?

Q = C\cdot \Delta T = 0.505 \times (25.00 - 14.14) = 5.4843\;\text{kJ} for 0.212162\;\text{mol}. By convention, the enthalpy change \Delta H measures the energy change for each mole of a process.

\displaystyle \Delta H = \frac{Q}{n} = \frac{5.4843\text{kJ}}{0.212162\;\text{mol}} = 25.8\;\text{kJ}\cdot\text{mol}^{-1}.

The heat capacity is the least accurate number in these calculation. It comes with three significant figures. As a result, round the final result to three significant figures. However, make sure you keep at least one additional figure to minimize the risk of rounding errors during the calculation.

You might be interested in
How many grams are in 5 mols of KOH​
elena55 [62]

Answer:

0.08911760029829444

Explanation:

hop that this what you wanted

8 0
2 years ago
What is the new pressure of gas?
Hunter-Best [27]
The pressure of a gas is the force that the gas exerts on the walls of its container. When you blow air into a balloon, the balloon expands because the pressure of air molecules is greater on the inside of the balloon than the outside. Pressure is a property which determines the direction in which mass flows.
4 0
3 years ago
Read 2 more answers
At their centers, all the jovian planets have cores made of:
Paul [167]

Answer:

The core of Jupiter and Saturn is made up of rock,metal and hydrogen compounds, while the core of Uranus and Neptune is made up of rock,metals,water, methane, and ammonia.

Explanation:

The Jovian planets include, Jupiter, Saturn, Uranus, and Neptune. These planets when compared to terrestrial planets are small, with dense cores and surrounded by layers of gas.

5 0
2 years ago
Low frequency waves have longer wavelength true or false
kap26 [50]

Answer:

True

Explanation:

Since the waves have low frequency that means the wavelength is going to be longer. Hope this helps

5 0
2 years ago
I need help with number 5
pochemuha
The answer is package c because each cd would cost $1.87, which is the lowest price
7 0
3 years ago
Other questions:
  • What are some signs of cyanide poisoning visible on a corpse?
    9·1 answer
  • What is the relationship between air resistance and surface area?
    13·1 answer
  • A 0.89% (w/v) sodium chloride solution is referred to as physiological saline solution because it has the sameconcentration of s
    13·1 answer
  • When 3.51 g of phosphorus was burned in chlorine, the product was a phosphorus chloride. Its vapor took 1.77 times as long to ef
    14·1 answer
  • Choose the correct coefficients for the equation? ____NaCI&gt;____Na+___C12​
    14·1 answer
  • CFx where x stands for a whole number. Measurements also show that a certain sample of the unknown compound contains 8.5 mol of
    12·1 answer
  • A compound is 70.0% iron and 30.0% oxygen. Its molecular mass is 479.1 g/mol. Determine the
    9·1 answer
  • Speed.
    15·1 answer
  • In a lab experiment 80.0 g of ammonia [NH3] and 120 g of oxygen are placed in a reaction vessel. At the end of the reaction 72.2
    8·1 answer
  • Question 2 (1 point)
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!