“Water” is the best thermal insulator.
Option: B
<u>Explanation</u>:
“Thermal insulators” are the materials which do not allow heat to transfer. “Water” is the substance which does not transfer heat. Hence, the “water” is the best “thermal insulator”. Water is the bad conductor of thermal heat. Water has “low thermal conductivity” than other substances, so this acts as an insulator as long as it is not traveled from one place to another. Heat is transferred when a “hot object collides” with “the cold objects”. The “thermal conductivity” of “water” is 0.6 W/m K.
Answer:
The change in concentration of H+ ions is -9.99×10⁻⁵
Explanation:
When pH rises, we talk about neutralization and, there is a decline in proton's concentration.
pH lower than 7 is acid
pH higher than 7 is basic
Protons are neutralized by hydroxides to make water as this:
H₃O⁺ + OH⁻ ⇄ H₂O
pH = - log [H₃O⁺]
[H₃O⁺] = 10^-pH
In conclussion: [H₃O⁺]₁ = 10⁻⁴ → 1×10⁻⁴
[H₃O⁺]₂ = 10⁻⁷ → 1×10⁻⁷
1×10⁻⁷- 1×10⁻⁴
The change in concentration of H+ ions is -9.99×10⁻⁵
Answer:
TRUE
Explanation:
Principal shell 2n has one s and one p subshell, and can hold a total of eight electrons. The p subshell has three dumbbell-shaped orbitals, as illustrated in Figure 4.
Molar mass sucrose :
C12H22O11 = 342.29 g/mol
number of moles <span>of the solute :
</span>
n = mass solute / molar mass
n = 17.1 / 342.29
n = 0.05 moles
Volume in liters :
250 mL / 1000 = 0.25 L
therefore :
Molarity = moles of solute / volume
Molarity = 0.05 / 0.25 => 0.2 mol/L
