Whenever any substance goes under chemical change so any of the reaction will happen either both or multiple compounds will combine to produce combination reaction either one compound will decompose itself into 2 or more compounds or elements and last one is replacement reaction the either reaction is not even going to combination nor decomposition, So when a reaction like that happens it must replacement reaction.
Now the question is what's the condition required for it, so basically a chemical reaction when takes place it depends upon several factor on the basis of which we conclude products. The factors are Temperature,catalyst,reagents, either what is the mechanism of reaction, stability of reactants and stability of products and alot more.
During reaction sometimes gas forms and sometimes not yea and well that also depends on the chemical reactivity and stability of product sometimes product found itself most stable releasing the gas evolving so it's been done itself and sometimes we add catalyst and adjust the reaction to extract that gas and get desirable product manually.
I wrote all i know if sorry if this is not what you're looking for :(
<u>Answer:</u> The mass of phosphorus that is present for given amount of calcium is 28.53 g.
<u>Explanation:</u>
We are given:
Mass of calcium = 50 grams
The chemical formula of calcium phosphate is 
Molar mass of calcium = 40 g/mol
Molar mass of phosphorus = 31 g/mol
In 1 mole of calcium phosphate, 120 grams of calcium is combining with 62 grams of phosphorus.
So, 50 grams of calcium will combine with = 
of phosphorus.
Hence, the mass of phosphorus that is present for given amount of calcium is 28.53 g.
Answer:
Technician B.
Explanation:
The claim of technician B that the PCM will add fuel if the IAT indicates that the incoming air temperature is cold is correct.
The answer is A. In case you wanted to know, the actual answer is 4.184. If anything is unclear, just ask!
