The oldest known organic compound is

Correct Answer: A solution is a homogeneous type of mixture of two or more substances A solution has two parts:: 1 A solute and 2 A solvent The solute is the substance that dissolves, and the solvent is the majority of the solution

Correct Answer: 4

Explanation:

The main group number for an element can be found from its column on the periodic table. For example, carbon is in group 4 and has 4 valence electrons. Oxygen is in group 6 and has 6 valence electrons.

Correct Answer: FALSE

Explanation:

Nitrogen is found as a diatomic molecule (N2) in nature. There is a triple bond between the two nitrogen atoms.

 

The triple bond is pretty strong. Therefore, it needs a lot of energy to break those bonds and participate in a reaction. So nitrogen is commonly referred to as and used as an inert gas (high abundance & low cost.) However, it?s not truly inert like most noble gases. Nitrogen does react if the conditions are met. But those conditions are not exactly mild, but are not as extreme as for noble gases.

 

It forms nitric oxide and nitrogen dioxide with oxygen, ammonia with hydrogen, and nitrogen sulfide with sulfur.

Correct Answer: Milk

Explanation:

Milk is not a pure substance since it has so many constituents that can be separated physically.

Compounds are pure substances formed from elements unlike mixtures.

Correct Answer: TRUE

Explanation:

True, Water is a Pure substance and not a mixture.

 

We know that, A mixture is when two or more substances combine physically together. You can find that the mixture retains the properties of the original components.

In water, two hydrogen atoms combine with one oxygen atom chemically, forming a new substance that has properties different from hydrogen alone or oxygen alone.

 

Therefore, water is not a mixture; it is a compound and it is pure.

Correct Answer: Nitrogen

Correct Answer: 6CO2 + 6H2O -----> C6H12O6 + 6O2

Explanation:

Photosynthesis is a process used by plants and other organisms to convert light energy into chemical energy that can later be released to fuel the organisms activities.

 

Photosynthesis can be represented using a chemical equation.

 

The overall balanced equation is

 

               $$\begin{gathered} 6 CO 2 + 6 H 2 O ? Sunlight C 6 H 12 O 6 + 6 O 2 \\ S o u r c e o f C a r b o n & O x y g e n + \\ S o u r c e o f E l e c t r o n s & H y d r o g e n + \\ E n e r g y t h a t d r i v e s P h o t o s y n t h e s i s - - - - > \\ S u g a r + G a s p r o d u c e d b y s p l i t t i n g w a t e r . \end{gathered}$$

 

Where 

CO2 = carbon dioxide 

H2O = water

C6H12O6 = glucose 

O2 = oxygen.

Correct Answer: Both A & B

Explanation:

An Element is a pure substance of one type of atom. In chemistry, any material such as carbon, hydrogen, iron, or oxygen that cannot be broken down into more fundamental substances is nothing but an element.

Correct Answer: We know that polar substances are soluble in polar solvents and non polar substances are soluble in non-polar solvents only Here the hydrocarbons are non-polar molecular substances and water is a polar solvent So water can't dissolve hydrocabons Hence, as hydrocarbons are non-polar substances, they are insoluble in water as it is a highly polar solvent

Correct Answer: copper(II) hydroxide

Explanation:

Sodium chloride:

The solubility rules tell you that all halides are soluble with the exception of those formed with siver, mercury, and lead ions. Since this is not the case here, sodium chloride will be soluble.

 

Silver nitrate:

It is soluble because all nitrates are soluble, without exception.

 

Potassium sulfate:

It is soluble because all sulfates are soluble with the exception of those formed with silver, calcium, barium, mercury, lead, and strontium ions.

 

Copper (II) hydroxyde:

It is insoluble because all hydroxides are insoluble with the exception of those formed with alkali metal ions and barium.