Answer is: there are 3.011·10²³ atoms of calcium.
n(Ca) = 0.50 mol; amount of substance(calcium).
Na = 6.022·10²³ 1/mol; Avogadro's constant or number.
N(Ca) = n(Ca) · Na.
N(Ca) = 0.50 mol · 6.022·10²³ 1/mol.
N(Ca) = 3.011·10²³; number of calcium atoms.
The mole is an SI unit which measures the number of particles in substance. One mole is equal to <span><span>6.022</span></span>·<span><span><span>10</span></span></span>²³<span> atoms.</span>
Answer:
There is 37.36 grams of K3PO4 produced
Explanation:
Step 1: Data given
Mass of H3PO4 = 29.6 grams
KOH is in excess
Molar mass of KOH = 56.11 g/mol
Molar mass of H3PO4 = 97.99 g/mol
Step 2: The balanced equation
3KOH(aq) + H3PO4(aq) ⇔ K3PO4(aq)+3H2O(l)
Step 3: Calculate mass of KOH
Mass KOH = mass KOH / molar mass KOH
Mass KOH = 29.6 grams / 56.11 g/mol
Mass KOH = 0.528 moles
Step 4: Calculate moles of K3PO4
Since KOH is the limiting reactant, We need 3 moles of KOH for each moles of H3PO4, to produce 1 mole of K3PO4 and 3 moles of H2O
For 0.528 moles of KOH we'll have 0.528/3 = 0.176 moles of K3PO4
Step 5: Calculate mass of K3PO4
Mass K3PO4 = moles K3PO4 * molar mass K3PO4
Mass K3PO4 = 0.176 moles * 212.27 g/mol
Mass K3PO4 = 37.36 grams
There is 37.36 grams of K3PO4 produced
Answer: option D. The attractive forces between the sodium and chloride ions are overcome by the attractive forces between the water and the sodium and chloride ions.
Explanation:
<em>Solid sodium chloride</em> (NaCl) is a ionic compound formed by ionic bonds between by the positive, metallic cations of sodium atom, Na⁺, and the negative, non-meatllic anions of chlorine atom, Cl⁻ (chloride).
Ionic bonds, then, are the electrostatic attracion between oppositely charged particles (cations and anions).
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<em>When solid sodium chloride dissolves in water</em>, the ions (cations and anions) are separated in the solvent (water) due to the superior attracitve forces between such ions and the polar water molecules.
<em>Water</em> (H₂O) is a molecule, formed by polar covalent bonds between two hydrogen atoms and one oxygen atom.
The polarity of water molecule is due to the fact that oxygen atoms are more electronegative than hydrogen atoms, which cause that the electron density is closer to oxygen nuclei than to hydrogen nuclei. This asymmetry in the electron density conferes a partial positive charge over each hydrogen atom and a partial negative charge over the oxygen atoms.
Thus, the positively charged hydrogen atoms attract and surround the negative chloride (Cl⁻) anions, while the negatively charged oxygen atoms attract and surround the positive sodium (Na⁺) cations. It is only because the attractive forces between the water and the sodium and chloride ions are stronger than the attractive forces between the sodiium and chloride ions that such ions may be kept separated in the solution. This process is called solvation and the ions are said to be solvated by the water molecules.
River sources tend to be at the top of mountains or areas of high elevation. This means that rivers impact the entire terrain from mountains to seas and oceans.
I hope this Helps!
I'd say b, but i'm not 100 percent sure.<span />