Answer:
MCO3 is BaCO3
The mass of CO2 produced is 0.28g of CO2
Explanation:
The first step in solving the question is to put down the balanced reaction equations as shown in the image attached. Secondly, we obtain the relative number of moles acid and base as mentioned in the question. The balanced neutralization reaction equation is used to obtain the number of moles of excess acid involved in the neutralization reaction.
This is then subtracted from the total number of moles acid to give the number of moles of acid that reacted with MCO3. From here, the molar mass of MCO3 and identity of M can be found. Hence the mass of CO2 produced is calculated as shown.
0.0036g of NH4+ x 1mol of NH4+/18.04g of NH4+ x 6.02*10^23 electrons of NH4+/1mol of NH4+
= 1.20 x 10^20 electrons of NH4+
Answer:
E = 1.8 x 10⁵ J/mol
Explanation:
We are being asked the enery per mol for an emission line corresponding to 649 nm.
The energy of a photon is given by the porduct of Planck's contant times the frequency of the radiation,
E = hν
We also know that the frequency is given by
ν = c/λ
where c is the speed of light (3 x 10 ^8 m/s) and λ is 649 nm given in the problem. Therefore the energy per photon will be given by
E= hc/λ = 6.626 x 10⁻³⁴Js x 3 x 10 ^8 m/s/ 649 x 10 ⁻⁹ m
E = 3.1 x 10 ⁻¹⁹ J/ photon
(Note the wavelength has to be in nanometers (1nm= 10⁻⁹ m) and that the energy we get is the energy per a single photon. Thus we will need to multiply this result by Avogadro's number to answer this question.
E = 3.1 x 10 ⁻¹⁹ J/ photon x 6.022 x 10 ²³photon/mol
E = 1.8 x 10⁵ J/mol
Answer:
B
Explanation:
Because a ball falling down is a good strong force
Answer: The statement is true
Explanation:
The half-life of a radioactive isotope is the time taken for half of the total number of atoms in a given sample of the isotope to decay.
For instance
The half-life of radium is 1622 years. This means that if we have 1000 radium atoms at the beginning, then at the end of 1622 years, 500 atoms would have disintegrated, leaving 500 undecayed radium atoms
Thus, the statement is true