Answer:
5.71 g
Explanation:
Step 1: Write the balanced equation
2 K + Cl₂ ⇒ 2 KCl
Step 2: Calculate the moles corresponding to 12.0 g of KCl
The molar mass of KCl is 74.55 g/mol.
12.0 g × 1 mol/74.55 g = 0.161 mol
Step 3: Calculate the moles of Cl₂ needed to produce 0.161 moles of KCl
The molar ratio of Cl₂ to KCl is 1:2. The moles of Cl₂ needed are 1/2 × 0.161 mol = 0.0805 mol
Step 4: Calculate the mass corresponding to 0.0805 moles of Cl₂
The molar mass of Cl₂ is 70.91 g/mol.
0.0805 mol × 70.91 g/mol = 5.71 g
Answer:
The photoelectric effect
Explanation: hope it helps
<span>Soda ash is sodium carbonate, Na2CO3. One chemical property of this compound is its basicity, which is measured by the pKb. The pKb for sodium carbonate is 3.67. It is the result of the dissociation of Na2CO3 in water: Na2CO3 + H2O = Na HCO3 + Na (+) + OH(-). This pKb means that it is a highly basic compound. pKb = log { 1 / [OH-] }, so pKb is a measure of the concentrations of OH- ions, which is the basiciity of the compound. </span>
Answer:
Assume that 100 grams of C2H4 is present. This means that there are 85.7 grams of carbon and 14.3 grams of hydrogen.
Convert these weights to moles of each element:
85.7 grams carbon/12 grams per mole = 7 moles of carbon.
14.3 grams hydrogen/1 gram per mole = 14 moles of hydrogen.
Divide by the lowest number of moles to obtain one mole of carbon and two moles of hydrogen.
Since we know that there cannot be a stable CH2 molecule, multiply by two and you have C2H4 which is ethylene - a known molecule.
The secret is to convert the percentages to moles and find the ration of the constituents.
