<span>The part of making a solution that always releases energy is the overall change in forming the solution. The answer is letter D. Although letters A, B and C can be viable answers but, it is not always the case. There are some substances that when you mix or separate them requires more energy or less energy. An example would be w</span>hen the formation (or enthalpy of formation) of carbon
dioxide is negative, it means that it releases heat to the surroundings. When
it releases heat to the surroundings, the reaction is exothermic. Another example is when you mix baking soda and muriatic acid, the resulting mixture is colder. When it is cold, it means that the reaction is endothermic. So the best answer is letter D.
Answer:
6.142 moles of NaCl
Explanation:
We'll begin by writing the balanced equation for the reaction. This is given below:
2AlCl3 + 3Na2S —> Al2S3 + 6NaCl
Next, we determine the number of mole in 239.7 g of Na2S. This is illustrated below:
Mass mass of Na2S = 78.048g/mol
Mass of Na2S = 239.7g
Number of mole Na2S =..?
Mole = Mass /Molar Mass
Number of mole Na2S = 239.7/78.048 = 3.071 moles
Finally, we can obtain the number of mole of NaCl produced from the reaction as follow:
From the balanced equation above,
3 moles of Na2S reacted to produce 6 moles of NaCl.
Therefore, 3.071 moles of Na2S will react to produce = (3.071 x 6)/3 = 6.142 moles of NaCl
Answer:
The pressure occupied is 1, 8 atm.
Explanation:
We use the Boyle´s Mariotte ´s law: for a given mass of gas at constant temperature, the pressure and volume vary inversely proportionally: P1xV1= P2xV2. The unit of pressure is converted to mmHg in atm.
760 mmHg----1 atm
912 mmHg---x= (912 mmHg x 1 atm)/760 mmHg=1,2 atm
P1xV1= P2xV2
P2=P1xV1/V2= 1,2 atm x 12 L/ 8L= <em>1, 8 atm</em>
Answer is D
Balance the equation
