Answer:
<em>3.27·10²³ atoms of O</em>
Explanation:
To figure out the amount of oxygen atoms in this sample, we must first evaluate the sample.
The chemical formula for sodium sulfate is <em>Na₂SO₄, </em>and its molar mass is approximately 142.05
.
We will use stoichiometry to convert from our mass of <em>Na₂SO₄ </em>to moles of <em>Na₂SO₄</em>, and then from moles of <em>Na₂SO₄ </em>to moles of <em>O </em>using the mole ratio; then finally, we will convert from moles of <em>O </em>to atoms of <em>O </em>using Avogadro's constant.
19.3g <em>Na₂SO₄</em> · 
· 
·
After doing the math for this dimensional analysis, you should get a quantity of approximately <em>3.27·10²³ atoms of O</em>.
Answer:
The evidence showing that there is a chemical reaction taking place is the instantaneous temperature drop once the cold pack is shaken.
Explanation:
When an athlete applies a cold pack to the injury, they shake it before, mixing the water and <em>ammonium-nitrate fertilizer</em> inside the cold pack. This mixing is an endothermic reaction, which means it absorbs heat. In turn, the temperature falls to 35 F for around 10 minutes.
I will solve this question assuming the reaction equation look like this:
<span>MnO2 + 4 HCl ---> MnCl2 + Cl2 + 2 H2O.
</span>
For every one molecule of MnO2 used, there will be one molecule of Cl2 formed. If the molecular mass of MnO2 is 87g/mol and molecular mass of Cl2 is <span> 73.0 g/mol, the mass of MnO2 needed would be:
Cl mass/Cl molecular mass * MnO2 molecular mass=
25g/ (73g/mol) * (87g/mol) * 1/1= 29.8 grams</span>
Answer:
Before we start answering, the appropiate equation for the energy of an ionic bond should be written:
Where A1+, B2- are the charges of the ions and Ro is the interionic distance (the sum of the radii of the anion and cation). C is a constant depending on the ionic structure.
Explanation:
Examining the equation above, we have the following scenarios:
a) Doubling the radius of A1 would mean a decrease on the energy of the ionic bond.
b) Tripling the charge of A1 would also triple the energy of the ionic bond
c)Doubling the charges on A1 and B2 would quadruple the energy of the ionic bond.
d)Decreasing the radii of A1 and B2 to half their original values would double the energy of the energy bond.
Calcium ions have oxidation state 2+ => Ca (2+).
Bromime ions (bromide) have oxidation state 1- => Br (-).
So, to be neutral the compound has to have two Br (-) ions per each Ca(2+) ion.
That is represented in the chemical formula as Ca Br2, where the number 2 to the right of Br is a subscript meaning that there are two atoms of Br per each atom of Ca (the lack of subscript means 1 atom).
Answer: Ca Br2.
