Answer:
The correct answer is - 4-nitroaniline.
Explanation:
It is given that all three solid compounds salicylic acid + 4-nitroaniline + naphthalene are equal in the ratio in the mixture and then 1 gram of this mixture is dissolved in the diethyl ether and run a drop of the solution on TLC plate. This plate shows three spots.
The salicylic acid and naphthalene would stay dissolved in the diethyl ether solution due to the 4-nitroaniline could be extracted by adding aqueous acid and involve in the aqueous layer and thus spot of 4-nitroaniline would be with largest Rf value.
Answer:
It is known as asymmetric key cryptography it is also called public key cryptography.
Explanation:
Asymmetric key cryptography method makes use of two keys.One is used for encryption and the second one for decryption. The public key serves to encrypt plain text or verify a digital signature, while the private key is used to decrypt or decipher the encrypted text or to create a digital signature.
Answer: A) grinding coffee beans
Explanation:
A physical change is defined as a change in which there is alteration in shape, size etc. No new substance gets formed in these reactions.
A chemical change is defined as a change in which a change in chemical composition takes place. A new substance is formed in these reactions.
1. Grinding coffee : Only change in size takes place, thus a physical change
2. Baking a cake: the chemical reaction occurs by combination of flour with oxygen , thus a chemical change.
3.:converting water to hydrogen and oxygen: The decomposition iof water takes place, thus is a chemical change
4.Burning of coal: the chemical reaction occurs by combination of carbon with oxygen , thus a chemical change.
Answer:
35750.4 Joules
Explanation:
Using the formula as follows;
Q = m × c × ∆T
Where;
Q = amount of heat (joules)
m = mass of substance (g)
c = specific heat capacity (J/g°C)
∆T = change in temperature (°C)
According to the provided information,
mass (m) = 320.0 grams
c = 4.2 J/g°C
∆T = (50.8°C - 24.2°C) = 26.6°C
Q = ?
Using; Q = m × c × ∆T
Q = 320 × 4.2 × 26.6
Q = 35750.4 J
