What are the key features of J.J. Thomson’s experiment?

2. Classify the following solutions as acidic, basic, or neutral at 25OC.

PilotLPTM [1.2K]

Answer: a) pH = 13.00 : basic

b) $[H_3O^+]=1.0\times 10^{-12}$ : basic

c) pOH = 5.00 : basic

d) $[OH^-]=1.0\times 10^{-9}$ : acidic

Explanation:

pH or pOH is the measure of acidity or alkalinity of a solution.

pH is calculated by taking negative logarithm of hydrogen ion concentration.

$pH=-\log [H_3O^+]$

Acids have pH ranging from 1 to 6.9 and bases have pH ranging from 7.1 to 14.Neutral substances have pH of 7.

a) pH = 13.00

As pH is more than 7, the solution is basic.

b) $[H_3O^+]=1.0\times 10^{-12}$

Putting in the values:

$pH=-\log[1.0\times 10^{-12}]$

$pH=12$

As pH is more than 7, the solution is basic.

c) pOH = 5.00

$pH+pOH=14.0$

$pH=14.0-5.00=9.00$

As pH is more than 7, the solution is basic.

d) $[OH^-]=1.0\times 10^{-9}$

Putting in the values:

$pOH=-\log[1.0\times 10^{-9}]$

$pOH=9.00$

$pH+pOH=14.0$

$pH=14.0-9.00=5.00$

As pH is less than 7, the solution is acidic.

3 0

3 years ago

6. What is the wavelength (in meters) of the electromagnetic carrier wave transmitted by The Sports

Vsevolod [243]

Answer:

wavelength = 2.81 m

Explanation:

Given that,

The frequency of the Sports Fan radio station, f = 106.4 MHz

We need to find the wavelength (in meters) of the electromagnetic carrier wave. The relation between frequency and wavelength is given by :

$c=f\lambda$

Where,

$\lambda$ is wavelength

$\lambda=\dfrac{c}{f}\\\\\lambda=\dfrac{3\times 10^8}{106.4\times 10^6}\\\\\lambda=2.81\ m$

So, the wavelength of the electromagnetic carrier wave is 2.81 m.

8 0

2 years ago

A gas is contained in a thick-walled balloon. When the pressure changes from 45.0 bar to 96.0 bar, the volume changes from 1.20

notsponge [240]

P1 * V1 ÷ T1 = P2 * V2 ÷ T2

45 * 1.20 ÷ 314 = 96 * V2 ÷ 420

30,144 * V2 = 22,680

V2 = 22,680 ÷ 30,144

The new volume is approximately 0.75 liter.

I hope I helped

5 0

3 years ago

Read 2 more answers

Describe the benefits and the drawback of natural gas.

Finger [1]

When looking to power your equipment or vehicle with natural gas, the first question that springs to mind is: what is natural gas? A lot of people use natural gas in their homes for cooking and heating, but they don’t really give it some thought. So, let’s see what natural gas is and how it’s different from other forms of fossil fuels like oil and coal.

Natural Gas is a fossil fuel that exist in a gaseous state and is composed mainly of methane (CH4) a small percentage of other hydrocarbons (e.g. ethane). The use of natural gas is becoming more and more popular as it can be used with commercial, industrial, electric power generation and residential applications.

5 0

2 years ago

When 2 moles of Fe(s) react with Cl2(g) to form FeCl3(s) according to the following equation, 799 kJ of energy are evolved.

GenaCL600 [577]

Answer:

1. Exothermic.

2. -1598 kJ.

Explanation:

Hello!

1. In this case, according to the reaction, we can infer that 799 kJ of energy are evolved (given off, released) it means that the enthalpy of reaction is negative as the reactants have more energy than the products; which means this is an exothermic reaction.

2. Here, as we know that the enthalpy of reaction is -799 kJ/mol, we can compute the q-value as shown below, considering the reacted 2 moles of solid iron:

$q=2mol*-799 kJ/mol\\\\q=-1598kJ$

Which means that 1598 kJ of energy are evolved when 2 moles of solid iron react.

Best regards!

4 0

3 years ago