To find the number of electrons in a neutral gold atom look at it's atomic number. The atomic number is the number of protons in the element. For an atom to be neutral it needs the same number of electrons as protons, therefore the positive and negative charges will be balanced out. Gold's atomic number is 79 therefore it has 79 electrons.
<span>Well it depends on percentage by what, but I'll just assume that it's percentage by mass.
For this, we look at the atomic masses of the elements present in the compound.
Cu has an atomic mass of 63.546 amu
Fe has 55.845 amu
and S has 36.065 amu
Since there are 2 molecules of Sulfur for each one of Cu and Fe, we'll multiply the Sulfur atomic weight by 2 to obtain 72.13 amu
So we have not established the mass of the compound in amus
63.546 + 55.845 + 72.13 = 191.521
That is the atomic mass of Chalcopyrite. and Iron's atomic mass is 55.845
So to get the percentage, or fraction of iron, we take 55.845 / 191.521
Which comes out to 29.15% by mass
Mass of the sample is not needed for this calculation, but since the question mentions it I would go ahead and check if the question isn't also asking for the mass of Iron in the sample as well, in which case you just find the 29.15% of 67.7g</span>
The product that you obtain if you evaporate the water from the NaoH layer prior to acidifying the layer is salt of <u> para - tery-butyphenol</u>
<u><em>Explanation</em></u>
- Para-tery-butyphenol can be isolate after extracting it into NaOH solution through carrying out
- heating and then cooling,
- then 3M of HCl is added to acidify.
- Then ice bath is done if needed
- finally the precipitate is filtered.
- Para tery butyphenol can be used for production of alkylphenolic.
Answer:
A synthesis reaction is <em>a reaction that occurs when two or more reactants combine into one product.</em>
Explanation:
A reaction that occurs when two or more reactants combine into one product is called a synthesis reaction.
A reaction that occurs when one element within a compound is exchanged with another element is called a single replacement reaction.
A reaction that occurs when a substance combines with molecular oxygen, releasing light and energy is called combustion.
A reaction that occurs when a single substance breaks apart and forms two or more new substances is called decomposition.
