Answer:
Mass of hydrogen gas evolved is 0.0749 grams.
Explanation:
Total pressure of the gases = p = 758 mmHg
Vapor pressure of water = 23.78 mmHg
Pressure of hydrogen gas ,P = p - 23.78 mmHg = 758 mmHg - 23.78 mmHg
P = 734.22 mmHg = 
Temperature of of hydrogen gas ,T= 25°C =298.15 K
Volume of hydrogen gas = V = 0.949 L
Moles of hydrogen gas =n
PV = nRT (Ideal gas equation )

n = 0.03745 mol
Moles of hydrogen gas = 0.03745 mol
Mass of 0.03745 moles of hydrogen gas = 0.03745 mol × 2 g/mol = 0.0749 g
Mass of hydrogen gas evolved is 0.0749 grams.
Observe to to gather facts, by paying close attention towards what you are working on.
meanwhile, reference is the act or process on reaching to your conclusion, based on facts you already know .
The last photo because its molecular formula is C3H4.
Answer:
91.1835 nm
Explanation:
Given that the ionization energy of the oxygen molecule = 1314 kJ/mol
It means that
1 mole of oxygen molecules can be ionized by the energy = 1314 kJ = 1314000 J
1 mole of molecules contains 6.022 × 10²³ atoms
So,
6.022 × 10²³ atoms of oxygen molecules can be ionized by the energy = 1314000 J
1 atom require
of energy
Energy = 
Also
Where,
h is Plank's constant having value
c is the speed of light having value 
is the wavelength
So,
Also,
So, wavelength = 91.1835 nm
Answer:
Organ systems & their main functions
Explanation:
The chest bones Rib Cage & spine - protects the vital organs (heart, lung,liver) from injury & provides structural support for body.
Skin is the body's first line of defense & keeps the body warm. In case of any invading infection, fever - body temperature rise fights it.
Circulatory system (containing heart) & its body fluid blood - transports nutrients and oxygen to body cells
Endocrine system regulates growth, produces hormones - that target organs via bloodstream.