Answer:
1.52g NaHCO3 were in the original mixture.
Mass percent: 64.1%
Explanation:
When NaHCO3 heats it descomposition occurs as follows:
2 NaHCO3(s) → Na2CO3(s) + CO2(g) + H2O(g).
The loss in mass is because of the evaporization of CO2 and H2O. As both are in the same porportion, its molar mass is the sum of both compounds (44g/mol + 18g/mol = 62g/mol)
Loss in mass: 74.80g - 74.24g = 0.56g.
In moles:
0.56g * (1mol / 62g) = 0.00903 moles of gas.
As 1 mole of the gases comes from 2 moles of NaHCO3:
<em>Moles NaHCO3:</em>
0.00903 moles of gas * (2 moles NaHCO3 / 1 mole gas) = 0.018 moles NaHCO3.
In grams (Molar mass NaHCO3: 84g/mol):
0.018 moles NaHCO3 * (84g / mol) = 1.52g NaHCO3 were in the original mixture.
The mass of the mixture was:
74.80g - 72.428g = 2.372g
That means mass percent of NaHCO3 is:
(1.52g / 2.372g) * 100 = 64.1%
Answer:
C
Explanation:
<em>The </em><em>specific</em><em> </em><em>heat </em><em>capacity</em><em>=</em><em>quantity</em><em> of</em><em> </em><em>heat</em><em> </em><em>in </em><em>joule/</em><em>mass×</em><em>c</em><em>h</em><em>a</em><em>n</em><em>g</em><em>e</em><em> </em><em>in </em><em>temperature</em>
<em>from </em><em>this </em><em>question</em><em> </em><em>the </em><em>quantity</em><em> of</em><em> </em><em>heat</em><em> </em><em>is </em><em>7</em><em>5</em><em>2</em><em>5</em><em>0</em><em>,</em><em>the </em><em>mass </em><em>is </em><em>2</em><em>0</em><em>0</em><em>0</em><em> </em><em>and </em><em>the </em><em>change </em><em>in </em><em>temperature</em><em> </em><em>is </em><em>5</em><em>0</em><em>-</em><em>3</em><em>0</em>
<em>which </em><em>is </em><em>2</em><em>0</em>
<em>therefore</em>
<em>c=</em><em>7</em><em>5</em><em>2</em><em>5</em><em>0</em><em>/</em><em>2</em><em>0</em><em>0</em><em>0</em><em>×</em><em>2</em><em>0</em>
<em>c=</em><em>7</em><em>5</em><em>2</em><em>5</em><em>0</em><em>/</em><em>4</em><em>0</em><em>0</em><em>0</em><em>0</em>
<em>c=</em><em>1</em><em>.</em><em>8</em><em>8</em>
<em>I </em><em>hope </em><em>this </em><em>helps</em>
Answer:
1.27 atm.
Explanation:
The following data were obtained from the question:
Pressure (P) in torr = 968 torr
Pressure (P) in atm =...?
Thus, we can convert from torr to atm by doing the following:
Recall:
760 torr = 1 atm
Therefore,
968 torr = 968/760 = 1.27 atm
Therefore, 968 torr is equivalent to 1.27 atm.
Answer:
HCl
Explanation:
The best solvent for NaF is a polar liquid. The only liquid having a significant dipole moment among the options is HCl due to the large electro negativity difference between hydrogen and chlorine.
The polar solvent can interact with the NaF via its dipoles such that the NaF dissolves due to ion-dipole interaction.
Answer:
Ammonia is limiting reactant
Amount of oxygen left = 0.035 mol
Explanation:
Masa of ammonia = 2.00 g
Mass of oxygen = 4.00 g
Which is limiting reactant = ?
Balance chemical equation:
4NH₃ + 3O₂ → 2N₂ + 6H₂O
Number of moles of ammonia:
Number of moles = mass/molar mass
Number of moles = 2.00 g/ 17 g/mol
Number of moles = 0.12 mol
Number of moles of oxygen:
Number of moles = mass/molar mass
Number of moles = 4.00 g/ 32 g/mol
Number of moles = 0.125 mol
Now we will compare the moles of ammonia and oxygen with water and nitrogen.
NH₃ : N₂
4 : 2
0.12 : 2/4×0.12 = 0.06
NH₃ : H₂O
4 : 6
0.12 : 6/4×0.12 = 0.18
O₂ : N₂
3 : 2
0.125 : 2/3×0.125 = 0.08
O₂ : H₂O
3 : 6
0.125 : 6/3×0.125 = 0.25
The number of moles of water and nitrogen formed by ammonia are less thus ammonia will be limiting reactant.
Amount of oxygen left:
NH₃ : O₂
4 : 3
0.12 : 3/4×0.12= 0.09
Amount of oxygen react = 0.09 mol
Amount of oxygen left = 0.125 - 0.09 = 0.035 mol