<u>Answer:</u> The ionic compound formed is magnesium chloride having formula 
<u>Explanation:</u>
Ionic compound is defined as the compound which is formed by complete transfer of electrons from one atom to another atom.
The atom which looses the electron is known as electropositive atom and the atom which gains the electron is known as electronegative atom. This bond is usually formed between a metal and a non-metal.
Magnesium is the 12th element of the periodic table having electronic configuration of 
This element will loose 2 electrons to form
ion
Chlorine is the 17th element of the periodic table having electronic configuration of 
This element will gain 1 electron to form
ion
So, for every 1 atom of magnesium, 2 atoms of chlorine are required. Thus, the chemical formula becomes 
Hence, the ionic compound formed is magnesium chloride having formula 
Answer:
Approximately 75%.
Explanation:
Look up the relative atomic mass of Ca on a modern periodic table:
There are one mole of Ca atoms in each mole of CaCO₃ formula unit.
- The mass of one mole of CaCO₃ is the same as the molar mass of this compound:
. - The mass of one mole of Ca atoms is (numerically) the same as the relative atomic mass of this element:
.
Calculate the mass ratio of Ca in a pure sample of CaCO₃:
.
Let the mass of the sample be 100 g. This sample of CaCO₃ contains 30% Ca by mass. In that 100 grams of this sample, there would be
of Ca atoms. Assuming that the impurity does not contain any Ca. In other words, all these Ca atoms belong to CaCO₃. Apply the ratio
:
.
In other words, by these assumptions, 100 grams of this sample would contain 75 grams of CaCO₃. The percentage mass of CaCO₃ in this sample would thus be equal to:
.
Answer: a low
and low pH.
Explanation:
pH is the measure of acidity or alkalinity of a solution.
pH is calculated by taking negative logarithm of hydrogen ion concentration.
![pOH=-log[OH^-]](https://tex.z-dn.net/?f=pOH%3D-log%5BOH%5E-%5D)
Thus as pOH and
are inversely related, a solution having higher pOH will have less amount of
concentration. And a solution having more pOH will have less pH.
Thus a substance with a high pOH would likely have low
concentration and low pH.
1 CH4 (g) + 2 O2 (g) -----> CO2 (g) + 2H2O(l) ΔH= - 890 kJ
1 mol 2 mol
1) If ΔH has minus, it means "release". We need only "release" choices.<span>
2) From reaction
1 mol </span>CH4 (g) "releases" ΔH= - 890 kJ - We do not have this choice.
2 mol O2 (g) "release" ΔH= - 890 kJ, so
1 mol O2 (g) "release" ΔH= - 445 kJ
Correct answer is B.
In neutralization process or titration process, we use the formula;
(M1V1)H3PO4 = M2V2(Ca(OH)2)
M1 = 0.600 m
V1 = 10.0ml
M2 = unknown
V2 = 12.5ml
M1V1 = M2V2
0.6*10 = 12.5*M2
M2 = (0.6*10)/12.5 = 0.48m
Therefore, the answer is 0.480m