- Two hydroxide ions means two OH^- ions .
- The valency of reactants must be 2
Only possible with alkaline earth metals
Let's see an example
- X belongs to group || i.e alkaline earth metals
The elements are
- Magnesium (Mg)
- Calcium (Ca)
- Beryllium(Be)
- Scandium(Sc)
- Barium (Ba)
- Renedium (Rn)
Option C is correct
Answer:
0.036 moles of gas are contained in 890.0 mL at 21.0 C and 0.987 atm
Explanation:
Ideal gases are those gases whose molecules do not interact with each other and move randomly.
An ideal gas is characterized by three state variables: absolute pressure (P), volume (V), and absolute temperature (T). The relationship between them constitutes the ideal gas law, an equation that relates the three variables if the amount of substance, number of moles n, remains constant and where R is the molar constant of the gases:
P * V = n * R * T
where P represents the pressure of the gas, V its volume, n the number of moles of gas (which must remain constant), R the constant of the gases and T the temperature of the gas.
In this case:
- P= 0.987 atm
- V= 890 mL= 0.890 L (being 1 L= 1,000 mL)
- n= ?
- R= 0.082
- T= 21 °C= 294 °K
Replacing:
0.987 atm* 0.890 L= n* 0.082 * 294 K
Solving:
n= 0.036 moles
<u><em>0.036 moles of gas are contained in 890.0 mL at 21.0 C and 0.987 atm</em></u>
Number #2 is joule
In the SI system the unit of heat is the joule. The calorie was defined so that the heat capacity of water was equal to one.The heat capacity of a substance is the amount of heat required to raise the temperature of a defined amount of pure substances by one degree.
Number #3 is Endothermic
Why? I can't explain. I Just left class where they were just explaining that.
The Atacama Desert is a plateau in South America.
Covering a 1,000-kilometre strip of land on the Pacific coast.
West of the Andes mountains. It is the driest non-polar desert in the world.
In the late 1800s, Chile and Bolivia disputed this land in the Guerra del Pacífico (War of the Pacific) becaue both countries claimed to be rightful owners of this region that.
During the day, temperatures in the desert can reach around 40º C (104º F).
