Answer:
In polar Covalent bonds, the electrons which are in bonded shifts towards an atom which has more valance electrons.
<u>Explanation:</u>
We know if an atom takes the electron it acquires a negative charge whereas if it gives an electron it acquires a positive charge in the ionic bond. But here we are talking about covalent bonds. Covalent bonds are those in which atoms share the electron instead of completely giving off the electron. If the atoms are identical in case of covalent bond that is 2 hydrogen atoms then this type of bonding is called pure covalent bonds but if the atoms linked in covalent bonds are different then it is called polar covalent bonds.
In this, the bonding electrons will shift towards an atom which has more valence electron thereby acquiring the partial negative charges and the other atom will acquire a partial positive charge. For example, HCl. In this the Chlorine atom is having more valence electron than hydrogen atom, and hence Chlorine atom has a partial negative charge and Hydrogen atom has a partial positive charge.
Answer:
177253.125hrs
Explanation:
Given parameters:
Number of hours spend per day on phone = 6.25hrs
Unknown:
Average hours pend by an average American if they lived for 77.7yrs
Solution:
Let us find the number of hours an average American spends on their phone per year;
there are 365days in a year
Number of hours = 365 x 6.25 = 2,281.25hrs
Now, if they lived for 77.7yrs;
They will spend = 77.7 x 2,281.25 = 177253.125hrs
Answer:
True
Explanation:
Yes.
The distance that the molecules move depends on their solubility in the solvent and the size of the molecules. Heavy molecules will travel slower and therefore travel a shorter distance in the time the chromatography is run.
We know from such things as felt tip pens that colourings can be soluble in different solvents. Water soluble felt pens have colours that are - well - water soluble. Permanent felt pens have colours that are insoluble in water but that are soluble in another solvent. This could well be alcohol.
The water soluble colours may also be soluble in alcohol. The solubility in alcohol will be different from the solubility in alcohol, and so the Rf value ( the distance travelled) will also be different.
Because of the complicated shapes of the colours, the colours may not have the same order in the Rf values in the different solvents.
The physical method that can be used for obtaining a sample of salt from a small beaker of salt and water would be evaporation.
<h3>Separation of salt and water</h3>
A mixture of salt and water can be separated by a method known as evaporation. This is based on the assumption that the salt in question is a water-soluble salt.
In order to separate the salt/water mixture:
- Place the mixture in a suitable evaporating dish
- Boil the mixture until all the water evaporates.
- The remaining residue would be the salt
Care should be taken not to overheat the residue in order to avoid melting. Evaporation is generally used to separate a mixture of water and soluble salt. If the salt is insoluble, filtration using a suitable filter paper will filter off the salt while the water is collected as the filtrate.
More on evaporation can be found here: brainly.com/question/1097783
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Which physical method can be used for obtaining a sample of salt from a small beaker of salt water?
Answer:
Near the boiling point of the solvent
Explanation:
The process of recrystallization is hinged on the fact that the amount of solute that can be dissolved by a solvent increases with temperature. The process involves creation of a solution by dissolving a solute in a solvent at or near its boiling point. At the boiling point of the solvent, the solute has a greater solubility in the solvent; not much volume of the hot solvent is required to dissolve the solute.
Before the solution is later cooled, you can now filter out insoluble impurities from the hot solvent. The quantity of the original solute drops appreciably because impurities have been removed. At this lower temperature, the solution becomes saturated and the solute can no longer be held in solution hence it forms pure crystals of solute, which can be recovered.
Recrystallization must be carried out using the proper solvent. The solute must be relatively insoluble in the solvent at room temperature but more soluble in the solvent at elevated temperature.
