Answer:True
Explanation:
Water is said to be hard when it contains calcium ions or magnesium ions dissolved in it. These ions are able to react with soap in such a way that the soap is prevented from forming lather with the water. Hard water occurs when water passes over calcium or magnesium bearing minerals and dissolves some of it. Hardness due to the presence of calcium ions can easily be removed by boiling the water.
Probably the CO2 concentration. If the earth gets warmer by rising greenhouse gases (one of which is CO2), the amount of rainfall and precipitation increases. I am not an expert, but that's my first guess.
In diamond, The arrangement of carbon atoms follows a tetrahedral shape. Each carbon is attached to four other carbon
atoms, forming strong covalent bonds.This arrangement of the diamond is very durable and rigidity, that's why is necessary so many energy to break it.
On the other hand, graphite, has a different geometric
arrangement. the carbon atoms are arranged in 2D sheets and each carbon is linked to three other carbon atoms, forming
hexagonal rings that are easily broken.
This is an incomplete question, here is a complete question.
The change in internal energy for the combustion of 1.0 mol of octane at a pressure of 1.0 atm is -5084.1 kJ. You may want to reference (Pages 381 - 385) Section 9.6 while completing this problem. If the change in enthalpy is -5074.2 kJ, how much work is done during the combustion? Express the work in kilojoules to three significant figures.
Answer : The work done during the combustion is, 9.9 kJ
Explanation :
Formula used :
where,
w = work done = ?
= change in enthalpy = -5074.2 kJ
= change in internal energy = -5084.1 kJ
R = gas constant = 8.314 J/mol.K
Now put all the given values in the above formula, we get:
Thus, the work done during the combustion is, 9.9 kJ
Answer:
- About 18 g of NH₄Cl will precipitate.
Explanation:
The <em>table G</em> is the graph of the solubility curves for several solutes which is attached.
The second picture identifies the solubilities for the NH₄Cl at 50ºC and 10ºC.
The solubility of NH₄Cl at 50ºC is about 52 g/ 100 g of water.
The solubility of NH₄Cl at 10ºC is about 34 g / 100 g of water.
Then, at 50ºC 100 g of water saturated with NH₄Cl contains about 52 g of NH₄Cl and 100 g of water saturated with NH₄Cl contains 34 g of NH₄Cl.
The difference, 52g - 34 g of NH₄Cl shall precipitate:
52 g - 34 g = 18g ← answer