Answer:
The original concentration of ethanol was 18 % (v/v)
Explanation:
For the analysis of a sample, mostly dilutions are made of the original concentrated sample. The analysis results obtained from the diluted sample are then calculated for the concentrated samples.
According to the given data, the wine sample was diluted 75 times. This means that the initial concentration of ethanol was 75 times more than the final concentration i.e. 0.24 % (v/v). So mathematically:
original concentration (v/v)= final concentration (v/v) x times diluted
original concentration (v/v)= 0.24 % x 75
original concentration (v/v) = 18 %
To get the empirical formula of this compound, we take a basis of 100 grams which means each percentage is equivalent to 1 gram. Hence there is 32.39 grams sodium, 22. 53 grams sulfur and 45.07 grams oxygen. We convert each mass to their moles by dividing by their respective molar mass. Na: 1.408, S:0.704 and O:2.82. divide each with the lowest: Na: 2: S: 1 and O:4. Hence the formula is Na2SO4.
Answer:
ver explicacion
Explanation:
Los iones se forman cuando las especies químicas pierden o ganan electrones.
Las sustancias iónicas consisten en un ión positivo y negativo cuyas cargas se equilibran exactamente entre sí, por lo que el compuesto iónico es neutro.
Los átomos de metal se mantienen unidos por el enlace metálico. Esto implica la interacción entre iones metálicos cargados positivamente y un mar de electrones negativos. Las cargas positivas de los iones metálicos están exactamente equilibradas por el mar de electrones cargados negativamente, por lo que el metal es neutro.
On the other hand ammonia is a very dangerous chemical which has a pungent smell and effect the eyes of the user. Thus it kept always in the fume exhaust hood for storing and dispensing function.
The pH of ammonia buffer contains ammonium hydroxide (NH₄OH) and a salt of ammonia with a strong acid like (HCl) which produces, ammonium chloride (NH₄Cl) mixture. The evaporation rate of ammonia is so high at room temperature thus on opening of the buffer solution the ammonia get evaporated very fast and the concentration of ammonia decreases which affect the pH of the buffer solution.
Thus the reason to put ammonia buffer in fume hood is explained.
Given :
The distance between a point charge and a neutral atom and is multiplied by a factor of 5.
To Find :
By what factor does the force on the neutral atom by the point charge change.
Solution :
We know, electrostatic force between two object is directly proportional to product of charge and inversely proportional to distance between them.
Now, charge in neutral atom is 0 C.
So, the electrostatic force between two of them is also 0 N.
Therefore, by changing distance between the charge the forces did no change ( it remains zero).
