Answer:
2H2(g) + O2(g) --------> 2H2O(g). ∆H= -242KJmol-1
Explanation:
A thermochemical equation is a balanced chemical reaction equation that includes the physical states of all reactants and products and the energy change.
As shown above, hydrogen reacted with oxygen in the gas phase to form water, an energy of 242KJ was evolved and we are required to put this in a thermochemical equation using the least coefficients.
Hydrogen reacts with oxygen to form water in the gas phase in a least ratio of 2:1 as shown in the answer.
The term 'energy evolved' in the question means that the reaction is exothermic and energy is evolved. Hence ∆H is negative as shown.
Answer:
Answer is explained below in the explanation section
Explanation:
Smaller signal is observed at a mass 1 amu because small percentage of the compound will have carbon isotope of 13C instead of 12C.
As we know, mass spectrometry is done as a small compound is first vaporized and then bombarded to ionize it. And then, those ions are accelerated forward and then at some point ions are separated and deflected by the application of magnetic field.
And finally hits the detector to give us a spectrum to read. So, in this whole procedure, there can be a small percentage of carbon isotope of 13C instead of 12C in that compound and showed in the spectrum as a smaller signal at a mass 1 amu.
I think the correct answer from the choices listed above is option A. The three components of air are all <span>classified as pure substances since they are not chemically bonded so they can be separated by certain processes and be present as a pure substance. Hope this answers the question.</span>
Atomic # 30
Atomic mass- 65.409g
Symbol- Zn
protons = electrons,
so 30 protons,30 electrons and 35 neutrons.
The atomic mass is also found by adding the protons and neutrons.
It can be found in group 12,period 4. Zinc is a transition metal.
Zinc has an oxidation state of 2+.
Melting point- 420 C
Boiling point- 907 C
Typical compounds formed are: zinc oxide, zinc sulfide and zinc nitrate.
According to records, a German scientists named Andreas Margraf discovered the element in 1746. Even though he was recognized for the discovery, historians agree ancient people created statues with some amount of zinc.
Zinc can be found in united states, Canada and Australia.
Hope this helps!
Answer:
D. These elements have properties of both metals and nonmetals.
Explanation:
It can be concluded that the elements have properties of both metals and non-metals.
The elements that borders the ones described are both metals and non-metals. Most of these elements can be classified as metalloids.
On the periodic table, the elements around this region have properties of both metals and non-metals at certain temperature and pressure conditions.
