Answer:
5 degrees required for ice
Answer:
Amount of gas
Explanation:
The combined gas law has to do with pressure, volume, and temperature. All of them can be a variable that you have to solve for. However, amount of gas is not a variable you can solve for, which means it must remain constant.
1.05 moles of oxygen gas are consumed in the reaction when 2.10 mol of magnesium burns.
<h3>What are moles?</h3>
A mole is defined as 
of some chemical unit, be it atoms, molecules, ions, or others. The mole is a convenient unit to use because of the great number of atoms, molecules, or others in any substance.
We are given:
Moles of magnesium = 2.10 mol
For the given chemical reaction:
2Mg + O₂ → 2MgO.
By Stoichiometry of the reaction:
2 moles of magnesium react with 1 mole of oxygen gas.
So, 2.10 moles of magnesium will react with = 
X2.10 =1.05 moles
Hence, 1.05 moles of oxygen gas are consumed in the reaction.
Learn more about moles here:
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Answer : The pH of calcium acetate solution will be 9.38.
Explanation : When calcium acetate dissocates completely in solution to form Calcium(+2) ions and two acetate ions, this gives the acetate ion concentration as
(2 X 0.51 M) = 1.02 M
Acetate ion then hydrolyzes as follows;
:
Now, Kb will be = ![[HC_{2}H_{2}O_{2}] [OH^{-}]](https://tex.z-dn.net/?f=%20%5BHC_%7B2%7DH_%7B2%7DO_%7B2%7D%5D%20%20%5BOH%5E%7B-%7D%5D)
/ ![[C_{2}H_{3}O_{2}^{-}]](https://tex.z-dn.net/?f=%5BC_%7B2%7DH_%7B3%7DO_%7B2%7D%5E%7B-%7D%5D%20)
= Kw / Ka
= 1 x 
/ 1.8 x 
= 5.6 × 
![[OH^{-}]](https://tex.z-dn.net/?f=%20%5BOH%5E%7B-%7D%5D%20)
= 2.4 ×
Now, we know , pOH = -log = 4.62
So, the pH = 14 - pOH = 14 - 4.62 = 9.38
Answer:
1.2 cm³.
Explanation:
The following data were obtained from the question:
Mass of neckl = 40 g
Density of gold = 19.3 g/cm³
Volume of gold =..?
Next, we shall determine the mass of the gold in the necklace.
From the question given above, we were told that 58% of the mass of the necklace is gold. Thus, we can obtain the mass of the gold in the necklace as follow:
Mass of neckl = 40 g
Mass of gold =?
Mass of gold = 58% × 40
Mass of gold = 58/100 × 40
Mass of gold = 23.2 g
Therefore, the mass of the gold in the necklace is 23.2 g
Finally, we shall determine the volume of the gold in the necklace as follow:
Density of gold = 19.3 g/cm³
Mass of gold = 23.2 g
Volume of gold =..?
Density = mass /volume
19.3 = 23.2/Volume
Cross multiply
19.3 × Volume = 23.2
Divide both side by 19.3
Volume = 23.2 / 19.3
Volume of gold = 1.2 cm³
Therefore, the volume of the gold in the necklace is 1.2 cm³
