I think it’s A
because if the pH is lower than 7 than it is acidic
Because they raise the activation energy
27) mechanical weathering
28) overgrowth of algae that produce toxins
29) Weathering breaks down and loosens the surface minerals of rock so they can be transported away by agents of erosion such as water, wind and ice. There are two types of weathering:mechanical and chemical. Mechanical weathering is the disintegration of rock into smaller and smaller fragments.
30) I'M NOT SURE
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The molecular formula of a compound is C₂H₂O₄.
Take 100 grams of compound:
1) ω(C) = 26.7% ÷ 100% = 0.267
m(C) = ω(C) × m(compound)
m(C) = 0.267 × 100 g.
m(C) = 26.7 g.
n(C) = m(C) ÷ M(C).
n(C) = 26.7 g ÷ 12 g/mol.
n(C) = 2.22 mol; amount of carbon
2) ω(H) = 2.2 % ÷ 100% = 0.022
m(H) = 0.022 × 100 g.
m(H) = 2.2 g.
n(H) = 2.2 g ÷ 1 g/mol.
n(H) = 2.2 mol; amount of hydrogen
3) ω(O) = 71.1 % ÷ 100%.
ω(O) = 0.711
m(O) = 0.711 × 100 g
m(O) = 71.1 g
n(O) = 71.1 g ÷ 16 g/mol
n(O) = 4.4 mol; amount of oxygen
4) n(C) : n(H) : n(O) = 2.2 mol : 2.2 mol : 4.4 mol /2.2 mol.
n(C) : n(H) : n(O) = 1 : 1 : 2
M(CHO₂) = 45 amu; empirical formula
90 amu ÷ 45 amu = 2 CHO₂
More info about empirical formula: brainly.com/question/1873039
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