Answer:
no of formula unit = 
Explanation:
atomic mass of CaCl2 = 40 + 2×35.5 = 111 g.
no of formula unit = no of moles × Avagadro number
=
When you cook food like eggs, this is a chemical change. Agree.
The runny egg turns into a solid. One type of matter must be changing into another type
When you cook food like potatoes, this is a chemical change. Agree.
Boiling potatoes causes changes in the structure of the starch. Higher heat as in baking, roasting, or frying causes the development of a harder crust on the potato. This suggests that chemical changes have taken place.
When a candle burns, the wick of the candle and wax turn into nothing. Disagree.
The <em>Law of Conservation of Mass</em> says that <em>you can’t turn matter into nothing</em>. What must be happening is that the wick and the wax are changing into other substances that we can’t see, such as colourless gases of carbon dioxide and water vapour.
Answer:
B. SONAR (Sound Navigation Ranging)
Explanation:
Just took the test
There are two oxygen atoms in an oxygen molecule. Denoted by the 2 following O
Answer:
2.5 atm
Explanation:
V1 = 28L
T1 = 45°C = (45 + 273.15)K = 318.15K
V2 = 34L
T2 = 35°C = (35 + 273.15)K = 308.15k
P2 = 2.0atm
P1 = ?
From general gas equation,
(P1 × V1) / T1 = (P2 × V2) / T2
P2 × V2 × T1 = P1 × V1 × T2
P1 = (P2 × V2 × T1) / (V1 × T2)
P1 = (2.0 × 34 × 318.15) / (28 × 308.15)
P1 = 21634.5 / 8628.2
P1 = 2.5 atm
The initial pressure of the gas is 2.5atm
