The answer is "<span>An atomic nucleus is positively charged because it is composed of protons". An atomic nucleus actually contains nucleons which are made up of both protons and neutrons. Since neutrons are neutral or have no charge, the charge of an atomic nucleus mainly relies on the positive charge of the protons.</span>
Answer and Explanation:
The balanced chemical equations are as follows:
The chemical formula of oxalic is 
In the case when oxalic acts reacted with the water so here the oxalic acid eliminates one proton that leads to the development of mono acids
After that, the second step derives that when oxalic acid is in aqueous solution eliminates other proton so it represent the polyprotic acid
Now the chemical equations are as follows:
Elimination of one proton
Now the elimination of other proton
<u>Answer:</u>
<em>Silver tarnishing as the silver metal reacts with sulphur is a chemical change.</em>
<u>Explanation:</u>
Tarnishing is the process of chemical change occurring on the surface of objects leading to corrosion or other defects on the surface. The remaining options like dilution, eroding is a physical change where the concentration of salt and rock particles will be decreased, respectively.
Similarly for soil drying also the concentration of water will be decreased leading to a physical change from wetty or dry soil.
But the last option which indicates tarnishing of silver metal on reaction with sulphur is a chemical process as the surface of silver metal will be reacting to sulphur and leads to lose of electrons which leads to corrosion of the surface or tarnishing of silver.
Answer:
94.325 g
Explanation:
We'll begin by converting 350 mL to L. This can be obtained as follow:
1000 mL = 1 L
Therefore,
350 mL = 350 mL × 1 L /1000 mL
350 mL = 0.35 L
Next, we shall determine the number of mole of KC₂H₃O₂ in the solution. This can be obtained as follow:
Volume = 0.35 L
Molarity of KC₂H₃O₂ = 2.75 M
Mole of KC₂H₃O₂ =?
Molarity = mole /Volume
2.75 = Mole of KC₂H₃O₂ / 0.35
Cross multiply
Mole of KC₂H₃O₂ = 2.75 × 0.35
Mole of KC₂H₃O₂ = 0.9625 mole
Finally, we shall determine the mass of KC₂H₃O₂ needed to prepare the solution. This can be obtained as illustrated below:
Mole of KC₂H₃O₂ = 0.9625 mole
Molar mass of KC₂H₃O₂ = 39 + (12×2) +(3×1) + (16×2)
= 39 + 24 + 3 + 32
= 98 g/mol
Mass of KC₂H₃O₂ =?
Mass = mole × molar mass
Mass of KC₂H₃O₂ = 0.9625 × 98
Mass of KC₂H₃O₂ = 94.325 g
Thus, the mass of KC₂H₃O₂ needed to prepare the solution is 94.325 g
Answer:
Ca(OH)2 molecular weight. Molar mass of Ca(OH)2 = 74.09268 g/mol. This compound is also known as Calcium Hydroxide. Convert grams Ca(OH)2 to moles or moles Ca(OH)2 to grams. Molecular weight calculation: 40.078 + (15.9994 + 1.00794)*2 ››
