To determine the heat required in order to decompose a certain amount of a substance, we need information on the heat needed to decompose one mole of the substance. This value are readily available online and other sources. For this reaction, the heat needed is 129 kJ per 2 mol of NaHCO3. We calculate as follows:
129 KJ / 2 mol NaHCO3 (1 mol / 84.01 g ) (25.5 g NaHCO3 ) = 19.58 kJ of heat is needed.
Answer:
Explanation:
Public tap water is not desirable when carrying out experiments in the laboratory.
The chemical definition of water is a compound made up of two atoms of hydrogen to 1 atom of oxygen. Any violation simply desist from the true meaning of water.
Why are tap water not used:
- They contain other dissolved ions like chlorine which have been added in their treatment. This alters the fundamental molecules that is expected to be seen in water. Water of this nature can affect experimental results seriously.
- Tap water can become a mixture instead of a simple compound. A mixture is a combination of several compounds. Such water will have a varied composition and make simplification of experiments very difficult.
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Here is the link to a great video that explains your question nicely, hope this helps.
The three factors determine the chemical properties of an element:
<span><span>The number and arrangement of electrons in an atom
</span><span>The number of valence electrons
</span><span>The number and arrangement of electrons</span></span>
Answer:
C. He shot tiny alpha particles through a piece of gold foil.
Explanation:
In the year 1911, Ernest Rutherford performed the gold foil experiment which gave a deeper perspective to the structure of an atom.
He simply collided a thin gold foil with an alpha particle which he generated from a radioactive source. He discovered that most of the alpha particles passed through the thin gold foil but a few were deflected back. His discovery led to the proposition of the nuclear model of the atom.