Answer: 0.4 g
Explanation:
1) Balanced chemical equation:
2) 2C2H2 + 5 O2 → 4CO2 + 2 H2O
3) mole ratios:
2 mol C2h2 : 5 mol O2
4) Convert 0.13 g C2H2 into number of moles
n = mass in grams / molar mass
molar mass C2H2 = 2 *12g/mol + 2*1 g/mol = 26 g/mol
n = 0.13 g / 26 g/mol = 0.005 mol
5) Set the proportion with the unknown
5 mol O2 x
----------------- = ---------------
2 mol C2H2 0.005 mol C2H2
x = 0.005 mol C2H2 * 5 mol O2 / 2 mol C2H2 = 0.0125 mol O2
6) Convert 0.0125 mol O2 to grams
mass = number of moles * molar mass
molar mass of O2 = 32 g/mol
mass = 0.0125 mol * 32 g/mol = 0.4 g
Answer: 0.4 g
Answer: There are 3 triple points in the given phase diagram.
Explanation: Triple point is defined as the point at which the temperature and pressure of the 3 phases are in equilibrium with each other.
In the given phase diagram, there are three points which is satisfying this definition.
Point A: At this point The monoclinic form and rhombic form have the same vapor pressure. Hence,

Point B: At this point, the monoclinic form starts to melt. Hence,

Point C: At this point, the rhombic form, monolinic form and liquid is in equilibrium. Hence,

Hence, this system has 3 triple points.
Answer:
you see I didnt read it and I'm just guessing and I think its C
The element above has 7 (OPTION D) valence electrons. This is because on the second shell, two electrons occupy the S orbital of the second shell (2s²)and five occupy the P orbital (2p⁵) , for a total of 7 valence electrons (1s² 2s² 2p⁵)
Use M1V1 = M2V2
11.9(8) = 1.5V2
95.2 = 1.5(V2)
V2 = 63.5 mL