Answer:
Explanation:
1)<u> Convert the distance, 13.1 km to miles</u>
1 = 1 mi / 1.61 km
- 13.1 km [ 1 mi / 1.61 km ] = 8.1336 mi
2)<u> Use 6.2 mi/h as a converstion factor between distance and time</u>
- 8.1366 mi × 1 / [6.2 mi/h] = 1.3124 h
3) <u>Convert 1.3124 h to minutes</u>
- 1.3124 h × [ 60 min/h] = 78.7 min
Rounding to the nearest minutes (two significant figures):
Mass of Co(NO₃)₂ = 1.95 g
V KOH = 0.350 L
[KOH] = 0.220 M
Kf = 5.0 x 10⁹
molar mass of Co(NO₃)₂ = 182.943 g/mol
so [Co(NO₃)₂] = 1.95 / (0.350 * 182.943) = 0.03045 M
[Co²⁺] = 0.03045 M
[OH⁻] = 0.22 M
chemical reaction:
Co²⁺(aq) + 4 OH⁻ ⇄ Co(OH)₄²⁻
I (M) 0.03045 0.22 0
C (M) - 0.03045 - 4 (0.03045) 0.03045
E (M) - x 0.22 - 4(0.03045) 0.03045
= 0.0982
Kf = [Co(OH)₄²⁻] / [Co⁺²][OH⁻]⁴
5.0 x 10⁹ = (0.03045) / x (0.0982)⁴
x = 6.5489 x 10⁻⁸
at equilibrium:
[Co²⁺] = 6.54 x 10⁻⁸
[OH⁻] = 0.0982 M
[Co(OH)₄²⁻] = 0.03045 M
Answer:
During a total lunar eclipse, the Earth lies directly between the sun and the moon, causing the Earth to cast its shadow on the moon.
Explanation:
98 elements are naturally forming elements.
Answer: 98
Carbon has 4 valence electrons so to gain a noble gas electron configuration, which has 8 valence electrons and is the most electrically stable, carbon needs 4 more electrons.
