Answer:2
Explanation:
Ba(OH)2 contains two oxygen atoms
BaSO4 contains four oxygen atoms.
This means that barium sulphate contains two more oxygen atoms than barium hydroxide in its formula. This is clearly seen from the two formulae shown above.
Answer:
- Molar mass = 608.36 g/mol
Explanation:
It seems the question is incomplete. However a web search us shows this data:
" Reserpine is a natural product isolated from the roots of the shrub Rauwolfia serpentina. It was first synthesized in 1956 by Nobel Prize winner R. B. Woodward. It is used as a tranquilizer and sedative. When 1.00 g reserpine is dissolved in 25.0 g camphor, the freezing-point depression is 2.63 °C (Kf for camphor is 40 °C·kg/mol). Calculate the molality of the solution and the molar mass of reserpine. "
The <em>freezing-point depression</em> is expressed by:
We put the data given by the problem and <u>solve for m</u>:
- 2.63 °C = 40°C·kg/mol * m
For the calculation of the molar mass:<em> Molality</em> is defined as moles of solute per kilogram of solvent:
- 0.06575 m = Moles reserpine / kg camphor
- 25.0 g camphor ⇒ 25.0/1000 = 0.025 kg camphor
We<u> calculate moles of reserpine:</u>
- 0.06575 m = Moles reserpine / 0.025 kg camphor
- Moles reserpine = 1.64x10⁻³ mol
Finally we use the mass of reserpine and the moles to calculate <u>the molar mass</u>:
- 1.00 g reserpine / 1.64x10⁻³ mol = 608.36 g/mol
<em>Keep in mind that if the data in your problem is different, the results will be different. But the solving method remains the same.</em>
Answer:
k = 23045 N/m
Explanation:
To find the spring constant, you take into account the maximum elastic potential energy that the spring can support. The kinetic energy of the car must be, at least, equal to elastic potential energy of the spring when it is compressed to its limit. Then, you have:
(1)
M: mass of the car = 1050 kg
k: spring constant = ?
v: velocity of the car = 8 km/h
x: maximum compression of the spring = 1.5 cm = 0.015m
You solve the equation (1) for k. But first you convert the velocity v to m/s:
The spring constant is 23045 N/m
Answer:
-1273.3
Explanation:
Enthalpy of formation of a compound is the amount of heat absorbed or evolved when one mole of the compound is formed from other compounds.
enthalpy of formation Of CO2 = 2 X -393.5 = -787
enthalpy of formation Of C2H5OH = 2 X -277.7 = -555.4
enthalpy of formation Of C6H12O6 = 69.1 (reverse sign) + (-787 + -555.4) = - 1273.3 Joules
Answer:
The molar mass of the protein is 12982.8 g/mol.
Explanation:
The osmptic pressure is given by:
π=MRT
Where,
M: is molarity of the solution
R: the ideal gas constant (0.0821 L·atm/mol·K)
T: the temperature in kelvins
Hence, we look for molarity:
= =5.584×10⁻³mol/l
As we have 2 ml of solution, we can get the moles quantity:
Moles of protein: 5.584×10⁻³
×2ml=1.117×10⁻⁵mol
Finally, the moles quantity is the division between the mass of the protein and the molar mass of the protein, so:
Moles=Mass/Molar mass
Molar mass= Mass/Moles=
=12982.8 g/mol
