Explanation:
<h3>PLA is a polyester produced by fermentation under controlled conditions of a carbohydrate source like corn starch or sugarcane. ... The starch is then mixed with acid or enzymes and heated. This process “breaks” starch into dextrose (D-glucose), or corn sugar.</h3>
<h3>PLA is a polymer made from high levels of polylactic acid molecules. </h3><h3>For PLA to biodegrade, you must break up the polymer by adding </h3><h3>water to it (a process known as hydrolyzing). Heat and moisture are required for hydrolyzing to occur.</h3>
<h3>PLA consists of renewable raw materials and is biodegradable in industrial composting plants. </h3><h3>However, due to the lack of infrastructure, it is difficult to </h3><h3>compost PLA industrially or to</h3><h3> recycle it.</h3>
<span>Various gases and liquids have different densities and combustion points.</span>
<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 answer is (b). As, vanadium is attached to five fluoride atoms, each flouride containing -1 oxidation state, hence five fluoride contains -5, to neutralize, vanadium should have +5 oxidation state.
