Answer:
pOH=9.9
Explanation:
pH=-log[H+]= -log[0.0000877]
=4.06
pOH+ pH=14
pOH=14-4.06= 9.91
First calculate for the molar mass of the given formula unit, CaCO₃. This can be done by adding up the product when the number of atom is multiplied to its individual molar mass as shown below.
molar mass of CaCO₃ = (1 mol Ca)(40 g Ca/mol Ca) + (1 mol C)(12 g of C/1 mol of C) + (3 mols of O)(16 g O/1 mol O) = 100 g/mol of CaCO₃
Then, divide the given amount of substance by the calculated molar mass.
number of moles = (20 g)(1 mol of CaCO₃/100 g)
number of moles = 0.2 moles of CaCO₃
<em>Answer: 0.2 moles</em>
Answer:
54g of water
Explanation:
Based on the reaction, 1 mole of methane produce 2 moles of water.
To solve this question we must find the molar mass of methane in order to find the moles of methane added. With the moles of methane and the chemical equation we can find the moles of water produced and its mass:
<em>Molar mass CH₄:</em>
1C = 12g/mol*1
4H = 1g/mol*4
12g/mol + 4g/mol = 16g/mol
<em>Moles methane: </em>
24g CH₄ * (1mol / 16g) = 1.5 moles methane
<em>Moles water:</em>
1.5moles CH₄ * (2mol H₂O / 1mol CH₄) = 3.0moles H₂O
<em>Molar mass water:</em>
2H = 1g/mol*2
1O = 16g/mol*1
2g/mol + 16g/mol = 18g/mol
<em>Mass water:</em>
3.0moles H₂O * (18g / mol) =
<h3>54g of water</h3>
Dipyrithione is a chemical with formula, C₁₀H₈N₂O₂S₂. This means that each molecule of the substance has two (2) atoms of nitrogen. By using the dimensional analysis and Avogadro's number, equal to 6.022 x 10²³, we calculate for the answer as shown below.
n = (8.2 x 10²⁴ atoms N)(1 molecule dipyrithione/ 2 atoms of N)(1 mole dipyrithione/ 6.022 x 10²³ molecules dipyrithione)
Simplifying,
n = 6.8 moles dipyrithione
<em>ANSWER: 6.8 moles</em>
10 decigrams are equivalent to 1 gram, so 2,100 grams are equivalent to 2100 x 10. This makes 21,000.
