Answer:
The heat energy released from the reaction is approximately 51.4791 kJ
Explanation:
The given parameters are;
The heat of the reaction of 2Cl (g) → Cl₂ (g) = -243.4 J
The given mass of Cl being converted to chlorine gas, Cl₂ = 15.0 g
From the reaction for the heat of formation, we have;
2 moles of chlorine produces 1 mole of Cl₂ to release 243.4 kJ of energy per mole of Cl₂
The mass of 1 mole of Cl ≈ 35.453 g
Therefore, from number of moles, n = Mass/(Molar Mass), we have;
The number of moles of chlorine, in 15.0 g of chlorine = 15.0/35.453 ≈ 0.423 moles
Therefore, given that 2 moles of Cl produces 1 mole of Cl₂, we have;
0.423 moles of Cl will produce 0.423/2 ≈ 0.2115 moles of Cl₂
The heat energy released from the reaction is therefore, H ≈ 0.2115 × 243.4 kJ = 51.4791 kJ.
Physical and chemical properties are used to describe and identify matter. Physical properties can be observed without changing the identity of the substance. Chemical properties can be observed by attempting to change the identity of a substance. What are two physical and chemical properties that you can use to help you identify a substance?
Extensive properties, such as mass and volume, depend on the amount of matter that is being measured. ... Both extensive and intensive properties are physical properties, which means they can be measured without changing the substance's chemical identity
The sun’s core is made of solid rock. True or false
Answer:
False
Explanation:
Heres what its made of:
The core is made of hot, dense plasma (ions and electrons), at a pressure estimated at 265 billion bar (3.84 trillion psi or 26.5 petapascals (PPa)) at the center. Due to fusion, the composition of the solar plasma drops from 68–70% hydrogen by mass at the outer core, to 34% hydrogen at the core/Sun center.
"Henry mixed salt and water together in a cup until he observed a clear solution. He measured the mass of the solution. Then he placed the cup outside for several sunny days during the summer. After a week, he observed that only solid salt remained in the cup and the mass had decreased. Henry concluded that a physical and chemical change occurred in this investigation."
Which statements correctly defend or dispute his conclusion?
A.)He is correct. Dissolving salt in water is a physical change, but evaporating the water is a chemical change. Formation of a solid is evidence that a chemical change occurred.
B.)He is correct. Evaporation is a physical change, but dissolving salt in water is a chemical change. The change in mass is evidence that a chemical change occurred.
C.)He is incorrect. Dissolving salt in water and evaporation of the water are both physical changes. The reappearance of salt is evidence that the change was reversible by a physical change, so it could not be a chemical change.
D.)He is incorrect. Dissolving salt in water and evaporation of the water are both chemical changes. The reappearance of salt is evidence that the change was reversible by a chemical change, so it could not be a physical change.
Answer:
C.)He is incorrect. Dissolving salt in water and evaporation of the water are both physical changes. The reappearance of salt is evidence that the change was reversible by a physical change, so it could not be a chemical change.
Explanation:
From the analogy of the problem presented, we can see that Henry is grossly incorrect. His conclusion from the process of the experiment he carried out is completely wrong.
Physical changes are changes that alters the physical properties of matter particularly the form and state.
Chemical changes leads to the formation of a new kind of matter.
We can see that since the salt was obtained back after evaporation, no change has occurred to it.
Therefore, evaporation in itself is a physical change process.
Answer:
c on ed
Explanation:
3
Which two elements are the most abundant in the Earth's crust?
OA. iron and magnesium
B. iron and nickel
Oc. silicon and magnesium
OD. silicon and oxygen
Novomatlan
Yes
Answer:
Look at the properties of Oxygen and Silicon - the two most abundant elements in the Earth's crust - by clicking on their symbols on the Periodic Table.
Explanation:
Answer:
D. silicon and oxygen
Explanation:
The most abundant elements on the earth's crust are silicon and oxygen. Silicon and oxygen forms a wide range of silicate minerals they are found in the crust.
There are many silicates which are derived from the basal units of silicon and oxygen combining together. Other atoms or elements then combines with the silicate framework.
Oxygen is about 46% abundant in the crust whereas silicon takes about 28% to be the second most abundant element on the crust.
Silicate minerals abounds in rocks and within the soil.
What part of the atom contains the protons and neutrons?
____ power is generated from the heat released when uranium atoms split in a process known as fission.