Answer:
See the answer below
Explanation:
<em>First, it should be understood that an endothermic reaction is one that absorbs energy in the form of heat from the surrounding.</em> The products of endothermic reactions usually have higher energy than their reactants. Hence, the ΔH° which is referred to as the enthalpy change is usually positive.
<u>Forgetting to cover the coffee-cup calorimeter means some of the heat energy absorbed by the reactants would be exchanged back to the surroundings - a loss.</u> It also means that the enthalpy change would be smaller compared to if the cup had been covered because some of the heat has been lost to the surrounding.
Answer:
<h2>chemoautotrophs</h2>
Explanation:
Such types of bacteria that oxidize inorganic compounds to obtain energy and use carbon dioxide as a carbon source to synthesize their food are known as chemoautotrophs such as iron-oxidizing bacteria, cyanobacteria, sulfur-oxidizing bacteria and some other. Chemoautrophic mode of nutrition is a type of autotrophic nutrition in which organisms have the ability to synthesized their own food by using chemical energy in the place of solar energy. The organismS that use solar energy to synthesize their food are known as photoautotrophic organisms such as plants and some other organisms.
A heterogeneous catalyst can be easily separated from reactants.
<u>Answer:</u> The concentration of 
ions are 2.797 ppm and 0.212 ppm respectively.
<u>Explanation:</u>
To calculate the mass of solution, we use the equation:
Volume of gold = 100 L = 100000 mL (Conversion factor: 1 L = 1000 mL)
Density of gold = 1.001 g/mL
Putting values in above equation, we get:
To calculate the concentration in ppm (by mass), we use the equation:
- <u>Calculating the concentration of calcium ions:</u>
Mass of 
ions = 0.280 g
Putting values in above equation, we get:
- <u>Calculating the concentration of magnesium ions:</u>
Mass of 
ions = 0.0220 g
Putting values in above equation, we get:
Hence, the concentration of ions are 2.797 ppm and 0.212 ppm respectively.
