Answer:
Only to elements are gases at room temperature and standard pressure.
Fluorine and chlorine.
Explanation:
The group 17 is called halogen.
There are five elements in halogen group.
All halogens required one electrons to complete the octet and to get the noble gas electronic configuration.
All halogen elements have seven valance electrons.
Halogen elements:
Fluorine, chlorine, Bromine, iodine and astatine
Fluorine is gas at room temperature which s 25°C and standard pressure which is 1 atm.
It is present in the from of F₂.
Chlorine is also gas at room temperature and standard pressure.
It is present in the from of Cl₂.
The bromine is liquid under these condition.
Iodine and astatine are solids.
As we move down the group their melting and boiling points increases.
D) 250l
Explanation :
250,000/1000
<span>it must be a compound of a polyatomic cation (i think ammonium might be the only</span>
<u>Answer:</u> The molarity of phosphoric acid is 0.05 M
<u>Explanation:</u>
A neutralization reaction is defined as the reaction in which an acid reacts with a base to form a salt and water molecule.
At equivalence, moles of acid becomes equal to the moles of base. The equation for the neutralization follows:
........(1)
where,
are the n-factor, molarity and volume of acid that is 
are the n-factor, molarity and volume of the base that is NaOH
Given values:

Plugging values in equation 1:

Hence, the molarity of phosphoric acid is 0.05 M