D because 0 is always ignorant in significant figures. hope that helps:)
Answer:
The change in T° is 47.1 °C
Explanation:
Calorimetry formula to solve this:
Q = m . C . ΔT
We replace the data gien:
635 J = 3.50×10⁻² kg . 0.385 J/g°C . ΔT
In units of C, we have g and the mass (m) is in kg. So let's convert it from kg to g → 3.50×10⁻² kg . 1000 g / 1kg = 35 g. Now we can determine the ΔT:
635 J = 35 g . 0.385 J/g°C . ΔT
635 J / 35 g . 0.385 J/g°C = ΔT
47.1°C = ΔT
Answer:
pH = 7
Explanation:
pH is defined as -log [H⁺]. In a solution of pH 5:
pH = -log [H⁺]
10^(-5) = [H⁺]
1x10⁻⁵M = [H⁺].
Then, this solution is diluted from 10mL to 1000mL (990mL of water + 10mL of the original solution). That means the solution is diluted:
1000mL / 10mL / 100 times.
If [H⁺] before dilution was 1x10⁻⁵M, after dilution will be:
1x10⁻⁵M / 100 = 1x10⁻⁷M
And pH:
pH = -log [H⁺]
pH = -log 1x10⁻⁷M
<h3>pH = 7</h3>
Humid air has higher pressure because of the heaviness of water humid air is lighter so it has lower pressure.
