Answer:
34.15% is the mass percentage of calcium in the limestone.
Explanation:
Mass of precipitate that is calcium oxalate = 140.2 mg = 0.1402 g
1 mg = 0.001 g
Moles of calcium oxalate = 
1 mole of calcium oxalate have 1 mole of calcium atom.
Then 0.001095 moles of calcium oxalate will have 0.001095 moles of calcium atom.
Mass of 0.001095 moles of calcium :
0.001095 mol × 40 g/mol = 0.04381 g
Mass of sample of limestone = 128.3 mg = 0.1283 g
Percentage of calcium in limestone:

34.15% is the mass percentage of calcium in the limestone.
A. Two electrodes separated by an electrolyte that can generate an electrical current.
Answer:
A decrease in [H3O+] and an increase in pH (option a)
Explanation:
Equilibrium of water is shown in this equation
2H₂O ⇄ H₃O⁺ + OH⁻
When you add NaOH, you are modifying [OH⁻]
NaOH → Na⁺ + OH⁻
In equilibrium of water, the [OH⁻] increases
2H₂O ⇄ ↓ H₃O⁺ + OH⁻ ↑
As the [OH⁻] increases, by Le Chatellier, the equilibrium tends to decrease [H₃O⁺].
If the [OH⁻] is higher, pH is also high so the solution of water and sodium hydroxide would be totally basic.
Answer:
the anwser is landforms can be created by erosion
Explanation:
Answer:
Water has the greatest ΔEN
ΔEN H₂O → 3.4 - 2.1 = 1.3 Option D.
Explanation:
We should find the Electronegativity data in the Periodic table for all the elements:
C : 2.6
O: 3.4
H: 2.1
S: 2.6
N: 3.0
a. ΔEN CO₂ → 3.4 - 2.6 = 0.4
b. ΔEN H₂S → 2.6 - 2.1 = 0.5
c. ΔEN NH₃ → 3 - 2.1= 0.9
d. ΔEN H₂O → 3.4 - 2.1 = 1.3