Answer: The first steps
Explanation: science
The mass of stars affect how they end.
Stars with greater mass sometimes end with supernovas, a giant explosion, which can result in black holes or neutron stars, or sometimes nothing.
A medium sized star can result in a planetary nebula, which then results in a white dwarf.
Haha hope this sorta helped :)
Answer is: pH of solution is 3,02.
c(benzoic acid) = 0,03 mol/dm³.
c(sodium benzoate) = 0,02 mol/dm³.
pKa(benzoik acid) = 3,19.
pH = ?
Henderson–Hasselbalch equation for buffers: pH = pKa + log(cs/ck)
pH = 3,19 + log(0,02/0,03)
pH = 3,19 - 0,176
pH = 3,02.
cs - concentration of acid.
Answer:
a) 7.94 x 10²³ molecules, b) 5.62 g SO2, c) 1.97 L
Explanation:
a) We need to first convert Cu2S to moles. Since molar mass of Cu2S is 159.14 g/mol, 14.0 g = 0.0880 mol. Using molar ratios (3 mol O2/2 mol Cu2S, 0.0880 mol of Cu2S = 0.132 mol O2. Since 1 mol contains 6.02 x 10²³ molecules, 0.132 mol O2 = 7.94 x 10²² molecules O2.
b) Since the molar ratios of Cu2S to SO2 is 1:1, 0.0880 mol of Cu2S produces 0.0880 mol SO2. To convert mol to grams, we use the molar mass of SO2 (64.06 g/mol) to figure out that 0.0880 mol SO2 = 5.63 g SO2.
c) At STP, 1 mol occupies 22.4 liters. 0.0880 mol SO2 x 22.4 L/1 mol = 1.97 L
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The answer should be d but it could be c
