Answer:
4
Explanation:
If I remember correctly, the atomic # will always be the same as the # of electrons
What volume of water is needed to make 5.41 M solution with 47.71 moles of HCL?
Answer:
0.113 liters
Explanation:
5.41 M / 47.71 moles = 0.113 liters
why do we need to rinse the mouth before collecting the saliva
You are given 250 mL of a 12.0 M solution of KNO3. To obtain a 5.0 M, to what volume does the solution need to be diluted to?
600 ml
104.17 mL
0.24 mL
60 mL
Answer:
600 mL
Explanation:
molarity 1 * volume 1 = molarity 2 * volume 2. So this means 12 * 250 = 3000 and divide that by 5 to get 600 mL.
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(11) Deduce the number of dyes in food colouring H.
(iii) Suggest why food colouring F does not move during the experiment.
(iv) Explain which two food colourings contain the dye that is likely to be the most soluble the solvent.
(b) Determine which food colouring contains a dye with R, value closest to 0.67
Show your working.
Answer:
(ii) 1 dye
(iii) Food coloring F is insoluble in the solvent
(iv) 'E' and 'H'
(b) Food colouring G
Explanation:
Paper chromatography principle is based on the rates of migration of chemicals across a sheet of paper which are different and it consists of a stationary phase such as the water in the paper and a mobile phase such as the solvent resulting in the partitioning of the components of the mixture across the paper
The solution components are positioned to start in one place from where they migrate and separate out on the chromatography paper
(ii) The number of components into which the food colouring 'H' separates into = 1
Therefore, the number of dyes in food colouring 'H' = 1 dye
(iii) Food coloring 'F' does not move because it is insoluble in the solvent, which is the mobile phase
(iv) The food colouring that contains the dye that is likely to be most soluble in the solvent are does for which the dyes travel furthest, which are;
Food coloring 'E' and 'H'
(b) Using a similar question solution found on 'tutor my self' website, we have;
The [tex]R_f[/tex] values are given as follows;
[tex]R_f = \dfrac{Distance \ moved \ by \ dye}{Distance \ moved \ by \ solvent}[/tex]
The distance moved by the solvent = 5 units
The distance moved by dyes in food colouring 'E' and 'H' = 4 units
The distance moved by dye in food colouring 'G' = 3.3 units
The distance moved by the second dye in food colouring 'E' = 2.7 units
By inspection, we get;
[tex]R_f[/tex] dye in food colouring 'G' = 3.3/5 = 0.66,
Therefore, the dye with [tex]R_f[/tex] value closest to 0.67 is the dye in food colouring 'G'.
5). At what temperature (K) will 0.854 moles of neon gas occupy 12.3 L at 1.95
atmospheres?
Answer:
338.38 K
Explanation:
Applying,
PV = nRT............... Equation 1
Where P = pressure, V = Volume, R = Temperature, n = number of moles, T = temperature.
Make T the subject of the equation,
T = PV/nR............. Equation 2
From the question,
Given: P = 1.95 atm, V = 12.3 L, n = 0.854 moles
Constant: R = 0.083 L.atm/K.mol
Substitute these values into equation 2
T = (1.95×12.3)/(0.854×0.083)
T = 338.38 K
what does the period number on the periodic table tell us?
Answer:
The period number on the Periodic table tells you the total number of orbits that the atom will have. In other words, the period number indicates the number of energy levels (or energy orbit) of an atom. For example, 1st period indicates that these elements possess 1 energy shell (or energy orbit).
Explanation:
How many moles of aluminum are in 54 grams
how many atoms are in 4.5 moles of Al?
Explanation:
4.5×6.022×10²³
27.099×10²³
According to Avogadro's number, there are 27.10×10²³ atoms in 4.5 moles of Al.
What is Avogadro's number?Avogadro's number is defined as a proportionality factor which relates number of constituent particles with the amount of substance which is present in the sample.
It has a SI unit of reciprocal mole whose numeric value is expressed in reciprocal mole which is a dimensionless number and is called as Avogadro's constant.It relates the volume of a substance with it's average volume occupied by one of it's particles .
According to the definitions, Avogadro's number depend on determined value of mass of one atom of those elements.It bridges the gap between macroscopic and microscopic world by relating amount of substance with number of particles.
Number of atoms can be calculated using Avogadro's number as follows: mass/molar mass×Avogadro's number.As 1 mole =6.023×10²³ atoms , thus,4.5 moles =4.5×6.023×10²³ = 27.10×10²³ atoms.
Thus, there are 27.10×10²³ atoms in 4.5 moles of Al.
Learn more about Avogadro's number,here:
https://brainly.com/question/11907018
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