What is the amount of heat absorbed when the temperature of 75 grams of water increases from 20.°C to 35°C

<h2>There are four distinct techniques used to separate mixtures that is : </h2>

Explanation:

Mixtures

They are formed when two or more substances are simply mixed in any ratio not chemically combined with each other.  

Characteristics  

• They can be homogeneous or heterogeneous in nature that is the constituents can be seen to have visible boundaries or they may appear to mix thoroughly.
• The Properties of mixtures are same as that of constituents.  
• The constituents can be separated by physical methods.  
• Their formations do not require or release energy as there is no bond formation or breakage involved.
• The Properties of mixtures like melting point & boiling points are not fixed.  

Let us discuss few techniques :

1. Evaporation

For example :To obtain colored component (Dye) from Ink

Materials Required : Watch glass ink (blue/ black) beaker , stand, burner.  

Procedure :  

• Take a beaker and fill it half with water.  
• Take  ink (Blue/ black) in the watch glass and place it on the mouth of the beaker
• Start heating the beaker and observe.  
• Heating is continued as long as the evaporation is taking place
• Heating is stopped when no any further change can be noticed on the watch glass  

Observation:  

Evaporation taking place from the watch glass can be seen  

Residue is left on the watch glass  

Conclusion drawn :

• it can be concluded that ,”Ink is not a pure substance but it is a mixture of dye in water which can easily be separated by evaporation method”.  
• Ink is not a single substance  

2, Centrifugal method

 For example : To separate cream from milk by using centrifuge method.  

Materials Required : Full cream milk centrifuging machine/milk churner, jug test-tubes.  

Procedure:  

• Take un-boiled cold milk in two test-tubes and place these test-tubes in a centrifuging machine
• Centrifuge it at high speed by using a hand centrifuging machine for two minute and observe.

Observation

Cream floating on the milk can be seen.  

Conclusion drawn

When milk is rotated at high speed then the suspended lighter particles (fats and protein molecules) bind with each other forming ‘cream’ and ‘skimmed milk’. The cream being lighter floats over the skimmed milk which can be removed easily.  

3. Sublimation

For example :To separate a mixture of common salt and ammonium chloride :  

Materials Required : China dish, tripod stand mixture of common salt and ammonium chloride glass funnel cotton and burner.  

Procedure:  

• Take the mixture of sand and ammonium chloride in a china dish.  
• Cover the china dish with an inverted glass funnel and place it on a tripod stand.  
• Put a loose cotton plug in the opening of the funnel so as to prevent the escape of ammonium chloride vapors.  
• Heat the china dish on a low flame and observe.  

Observation :  

•  White fumes (vapors) of ammonium chloride can be seen coming out of the mixture.  
• These white fumes start depositing as white solid on coming in contact with the cold, inner walls of the funnel.  
• Sand salt is left behind in the china dish.

Conclusion drawn: Ammonium chloride, being a volatile substance , changes into white vapors easily which deposits on the cold inner wall of the funnel. This ammonium chloride obtained is called the  

An electron has a negative charge. When an atom loses an electron, it becomes a positive ion.
When an atom of lithium loses an electron and becomes an ion, it has one less electron shell, so its radius is smaller than the radius of the atom.
The answer is 3.

Answer:

From 4.9 g of sulfuric acid 8.175 g of potassium sulfate is formed.

Explanation:

Given data:

Mass of H₂SO₄ = 4.9 g

Mass of K₂SO₄ formed = ?

Solution:

Chemical reaction:

H₂SO₄ + 2KOH    →    K₂SO₄ + 2H₂O

Number of moles of H₂SO₄:

Number of moles = mass/ molar mass

Number of moles = 4.9 g/ 98.1 g/mol

Number of moles = 0.05 mol

Now we will compare the moles of  H₂SO₄ with  K₂SO₄ .

                       H₂SO₄         :             K₂SO₄

                            1             :                  1

                       0.05           :             0.05

Mass of K₂SO₄:

Mass = number of moles × molar mass

Mass = 0.05 mol × 174.3 g/mol

Mass = 8.715 g

Thus, from 4.9 g of sulfuric acid 8.175 g of potassium sulfate is formed.

The statement that he true concerning the scientific method, would be that the initial step of asking a question is the start and or beginning of the scientific method, it is only through this can a hypothesis be formed from and ultimately an experiment to be performed.

I believe the correct response would be B.

Answer:

Observational data collected by doppler radar, radiosondes, weather satellites, buoys and other instruments are fed into computerized NWS numerical forecast models. The models use equations, along with new and past weather data, to provide forecast guidance to our meteorologists