The answer is Solid.
This is on account of the substances that develop a solid are packed in a settled, firmly pressed geometric plan.
Answer : The number of moles of oxygen needed are, 1.5 moles.
Explanation :
The balanced chemical reaction will be:

Now we have to calculate the moles of oxygen.
From the balanced chemical reaction we conclude that,
As, 6 moles of water vapor produces from 5 moles of oxygen
So, 1.80 moles of water vapor produces from
moles of oxygen
Therefore, the number of moles of oxygen needed are, 1.5 moles.
Answer:
The second option
Explanation:
Speed is defined at the rate at which distance changes with time. It is scalar quantity and it is expressed as shown below:
Speed = 
At constant speed the rate of change of distance with time is the same. On the second graph, this is noticeable. Both distance and time change at the same rate.
The initial concentration of the unknown acid is 0.1900 M.
Explanation:
Titration is a chemical method of analysis to know the concentration and volume of the unknown chemical or analyte.
The formula for the titration is:
Macid x Vacid = Mbase x V base
The volume must be in litres. The volume is given in ml it should be divided with 1000 to obtain values in litre.
Data given are:
volume of acid= 10 ml 0.01 L
Molarity of the acid = ?
volume of the NaOH or base = 15.4 ml or 0.0154 L (equivalence point of the base)
molarity of the base = 0.1234 M
Applying the formula and putting the values, we get
Macid x 0.01 = 0.1234 x 0.0154
Macid = 0.1900 M
The weak acid is having molarity of 0.1900 M against the strong base with molarity of 0.1234M.