Answer:
2.04 x 10⁻⁶ moles H₂O
Explanation:
To find the moles H₂O, you need to multiply the given value by Avogadro's Number. This number is a ratio between molecules and moles, thus granting you the way to convert between both units. It is important to arrange the ratio in a way that allows for the cancellation of units. The final answer should have 3 sig figs to match the sig figs of the given value (1.23 x 10¹⁸ molecules).
Avogadro's Number:
6.022 x 10²³ molecules = 1 mole
1.23 x 10¹⁸ molecules H₂O 1 mole
--------------------------------------- x ------------------------------------- =
6.022 x 10²³ molecules
= 2.04 x 10⁻⁶ moles H₂O
Chemical changes occur when a substance combines with another to form a new substance, called synthesis or, alternatively, decomposes into two or more different substances.
Answer:
See explanation
Explanation:
When an a heavy object and a light object are thrown down from the same height, the two objects are expected to hit the ground at the same time since the two objects are both accelerated to the same extent (approximately 10m/s^2) under gravity.
However, due to air resistance, the heavier object reaches the ground first before the lighter object.
Hence, when we drop a feather and a stone at the same time from a height the stone will hit the ground faster than the feather.
The periodic table to chart which arranges all of the unknown elements to the automatic numbers the columns in the periodic table are called families or groups the rows are called periods
Answer:
34.9 mL
Explanation:
First we <u>convert 23.6 g of LiBr into moles</u>, using its <em>molar mass </em>(86.845 g/mol):
- 23.6 g ÷ 86.845 g/mol = 0.272 mol LiBr
Now we can <u>calculate the required volume</u>, using the <em>definition of molarity</em>:
- Molarity = moles / liters
- liters = moles / Molarity
- 0.272 mol / 7.8 M = 0.0349 L
We can <u>convert L into mL</u>:
- 0.0348 L * 1000 = 34.9 mL
