Propanoyl chloride and propanoic acid can be differentiated by the chemical reactions given as below:

Propanoyl chloride reacts with few drops of water, to give hydrochloric acid and original carboxylic acid. On dipping blue litmus paper into it, it turns into red color.

On adding NaHCO3 , solution to each of them, propanoyl chloride will not react whereas propanoic acid will give brisk èfferevescence due to the evolution of CO2 .Read more on Sarthaks.com - https://www.sarthaks.com/919462/chemical-tests-distinguish-between-following-compounds-propanoyl-chloride-propanoic

Pure acids in the liquid state are exceedingly poor conductors of electricity. The fact that aqueous solutions of acids conduct electricity is definite evidence of the existence of ions in these solutions. Acids undergo dissociation in aqueous solution to form H+ ions.

When electricity is passed through an aqueous solution of an acid, the H+ ions reach the cathode and each H+ ion picks up one electron from the cathode to form H2 gas. Because of this reaction, an aqueous solution of acid conducts electricity.

HCl(aq) → H⁺(aq) + Cl^–(aq)

Excel formulas are used to perform calculations on data entered into the spreadsheet. Excel formulas start with an equal sign. Compound formulas involve more than one operator in a formula. These formulas are used to do simple as well as complex calculations. The user can also perform addition on character and string data types. Other operations such as subtraction, multiplication, division etc. are not allowed. The ‘&’ symbol is used for addition. Range is a rectangular area which consists of a group of cells.

You are suman, living at 152-B ,New colony,Guragaon. Write a letter to the post master of your locality, complaining that you have not received so far the gift parcel sent to you by your friend from the U.K.

37-L

rajeev nagar

meerut

18 may, 2019

The S.H.O

Uttar Pradesh Police

Subject: Rampant Chain-snatching Incidents

Sir,

I am writing this letter to express my deep concern over the nuisance of increasing crime rate in our locality, Rajeev Nagar, and the police’s lackadaisical approach to the gravity of the situation. The incidents jewellery and purse snatching, mobile snatching,eve-teasing are on the increase. There is an atmosphere of insecurity and fear in the entire locality. No resident dares to go even during the broad daylight, not to mention going out after the dark.

The most worrying factor is most of these crimes are being done by the teenagers. These crimes are the fallout of their unregulated and unmonitored overexposure to the internet.

It really pains to see young teenagers being caught by police. Quite ironically, they belong to families with respectable background.

Being elders it is our moral responsibility to prevent the youngsters from going astray. The schools, the parents, and the government must come together to solve this problem. I hope the concerned authorities will look into the matter and take immediate measures to nip this evil in the bud. I am hopeful that you will help me in sensitizing the concerned authorities, people and organizations by publishing this letter in your reputed daily.

Thanking you.

Yours truly

Nupur

Reflexive Relation

A relation in a set A is called reflexive relation if (a,a) ∈ R for every element a ∈ A.
Example:.
Let A = {1, 2, 3, 4,5,6,7,8,9,10} and define R = {(a, b) | a divides b}
We saw that R was reflexive since every number divides itself
Let A = {1, 2, 3, 4,5,6,7,8,9,10} and define R ={(1,1),(2,2),(2,3),(3,2),(4,4)}
We saw that R is not reflexive since every number is not present in R

The energy or potential applied in the electron-beam tube or system to increase the energy of the electrons and accelerate their speed is known as accelerating potential.

The negative potential of the collector plate at which the photoelectric current becomes zero is called stopping potential or cut-off potential. Stopping potential is that value of retarding potential difference between two plates which is just sufficient to halt the most energetic photoelectrons emitted.

Hacking is an attempt to exploit a computer system or a private network inside a computer. Simply put, it is the unauthorised access to or control over computer network security systems for some illicit purpose.

Mobile OS is the type of OS, that operates on Smartphones, Tablets, PDAs or other Digital Mobile devices. Several types of mobile operating systems are available in market as follows:
Android, BlackBerry, iOS, Windows etc.
Android is a Mobile OS which is based on Linux kernel and primarily designed for touch screen mobile devices.
It provides access to a wide range of useful libraries and tools that can be used to build rich applications. The latest version of Android operating system is Marshmallow 6.0.

Continuous increase in the profits of any enterprise is possible only by performing useful services to the society. Infact, objectives are needed in every area that influences the survival and prosperity of busi¬ness. Since a business has to balance a number of needs and goals, it requires multiple objectives.
The five multiple objectives of business are as follows:

1. Market standing : Market standing refers to the position of an enterprise in relation to its competitors. A business enterprise must aim at stronger market standing in terms of offering competitive products to its customers and serving them to their satisfaction.
2. Innovation : Innovation is the introduction of new ideas or methods in the way something is done or made. There are two kinds of innovation in every business, i.e.,
   (i) innovation in product or service.
   (ii) innovation in the various skills and activities needed to supply them.
3. Productivity : Productivity is calculated by comparing the value of outputs with the value of inputs. It is used as a measure of efficiency.
4. Physical and financial resources : Any business requires physical resources like plants, machines, offices, etc., and financial resources i.e. funds to be able to produce and supply goods and services to its
   customers.
5. Earning profits : One of the main objectives of business is to earn profits on the capital employed.
   Profitability refers to profit in relation to capital investment. Every business must earn a reasonable profit which is crucial for its survival and growth

Stanza 1
He stalks in his vivid stripes
The few steps of his cage,
On pads of velvet quiet,
In his quiet rage.

WORD MEANINGS
stalks – stride, to move quietly and slowly in a threatening way
vivid – bright
stripes – long narrow bands
pads – the soft part under the foot of the tiger
rage – anger

Exp – The poet sees a tiger locked in a concrete cell in the zoo. It is a very small cage. The tiger can hardly take a few steps along the length of the cage. He looks majestic as he slowly moves up and down in his cage. The sharp and clear stripes on his body are of strong bright colour. His pads are velvet soft. Inspite of all his strength, he now lies imprisoned behind the bars. The caged tiger is angry. He is full of rage, but is quiet because he knows that he is helpless here.

The distribution pattern of the Railway network.

• The northern plains with their vast level land, high population density and rich agricultural resources provided the most favourable condition for their growth.
• In the hilly terrains of the peninsular region, railway tracts are laid through low hills, gaps or tunnels.
• The Himalayan mountainous regions too are unfavourable for the construction of railway lines due to high relief, sparse population and lack of economic opportunities. Likewise,
• It was difficult to lay railway lines on the sandy plain of western Rajasthan, swamps of Gujarat, forested tracks of Madhya Pradesh, Chhattisgarh, Odisha and Jharkhand.
• The contiguous stretch of Sahyadri could be crossed only through gaps or passes (Ghats).
• The development of the Konkan railway along the west coast has facilitated the movement of passengers and goods.