2H2O2 decomposes into the products 2H2O + O2(g)
Answer:
D
Explanation:
In a Helium (He) atom, the atomic structure of the atom has 2 protons, 2 electrons and 2 neutrons. For an element X to be a Helium (He) atom, it must possess 2 protons. The number of neutrons present will determine its stability either if its probably radioactive or a natural occurring inert gas.
In option 1,
We have H-2. The symbol "H" is used to denote the element hydrogen in the periodic table and hydrogen has only 1 protons and 1 neutron making its mass number 2.
Option 2,
He -2 : here in this option, we have a helium atom, but with mass number of 2 only. Judging from the formula of mass number = protons + neutrons, we already have proton as 2, hence the number of neutrons there is zero (0)
Option 3,
He - 3 : just like in option 2, the only difference here is that the mass number is 3 hence making the number of neutrons just 1.
Option 4,
He - 4 : This option met the requirements of having 2 protons and 2 neutrons making a total of 4 which corresponds to the mass number.
The enthalpy for the reaction : ΔH = -132
<h3>Further explanation</h3>
Given
Reaction and the enthalpy
Required
the enthalpy
Solution
Hess Law
Reaction 1 reverse :
A + B = G + C ΔH = -277
Reactions 2 and 3 remain the same (unchanged)
C + F = A ΔH = 303
D = B + H ΔH = -158
Add up all the reactions and remove the same compound from two different sides
D + F = G + H ΔH = -132
Answer:
a solution of salt is homogeneous mixture
a sulution of muddy water is heterogeneous mixture
Explanation:
reason for salt and water as homogeneous mixture because water dissolves salt easily unlikely heterogeneous mixture in which water cannot dissolve mud in it
37.8 g CH2Br2 X (1 mol CH2Br2 / 173.83 g) = 4.60X10^-3 mol CH2Br2
<span>4.60X10^-3 mol CH2Br2 X (2 mol Br / 1 mol CH2Br2) X 6.02X10^23 atoms/mol = 5.54X10^21 bromine atoms.
I think this is the answer.</span>