Answer:
Molar mass = 94972.745 g/mol
Explanation:
Given data:
Density = 2.25 g/ml
Pressure = 700 mmHg
Temperature = 200°C
Molar mass = ?
Solution:
Density = 2.25 g/ml (2.25×1000 = 2250 g/L)
Pressure = 700 mmHg (700/760 = 0.92 atm)
Temperature = 200°C (200+273 = 473K)
Formula:
d = PM/RT
M = dRT/P
M = 2250 g/L × 0.0821 atm.L /mol.K × 473K / 0.92 atm
M = 87374.93 g/mol / 0.92
M = 94972.745 g/mol
4 moles of hydrogen = 4 * 1.008 = 4.032 grams
1 mole of helium = 4.003 grams
Difference is 4.032 - 4.003
= 0.029 g
The formula for molality---> m = moles solute/ Kg of solvent
the solute here is NH₃ because it's the one with less amount. which makes water the solvent.
1) let's convert the grams of NH₃ to moles using the molar mass
molar mass of NH₃= 14.0 + (3 x 1.01)= 17.03 g/ mol
15.0 g (1 mol/ 17.03 g)= 0.881 mol NH₃
2) let's convert the grams of water into kilograms (just divide by 1000)
250.0 g= 0.2500 kg
3) let's plug in the values into the molality formula
molality= mol/ Kg---> 0.881 mol/ 0.2500 kg= 3.52 m
Answer:
When a body moves in a circle with constant speed , it is said to be in uniform circular motion .
Explanation:
- When an object moves in a circular path , its direction changes at each point .
- This change in direction result in change of velocity (velocity is vector quantity which changes if direction of the object change) .However speed do not change (it is scalar quantity , not affected by Direction)
- The Change in velocity produce acceleration ( a = v - u)
- Hence The object always produce acceleration in uniform circular motion .So, Some force (centripetal force) is needed to keep the object in circular motion.
