First M stands for Molarity which is (moles of solute) / (Liters of solution). we also know that moles = (mass) / (molar mass). so we can form some equations here. We know:
Molarity (M) = moles (mol) / Liters (L)
moles (mol) = (mass) / (molar mass)
we can substitute the (mass) / (molar mass) for (moles) and get:
M = [(mass) / (molar mass)] / Liters
we can now isolate mass and get
M * Liters * molar mass = mass
now we need to find the molar mass of CaCl2 which is 110.98 g/mol
plug the values in and get
.350M * 6.5L * 110.98 g/mol = mass
mass = 252.4795g however the 6.5L has only 2 sig figs so i would say
mass CaCl2 = 2.5 * 10 ^2 g
The answer is 3.
That is if an atom has 5 electrons in its outer shell, then it has 3 unpaired electrons.
As the outer shell have 1 s orbital too and that is fully filled and not available for bonding so it must have 3 unpaired electrons.
So the number of unpaired electrons in an atom that is having 5 electrons in its outer shell is 3.
Answer: No.
Explanation: A negative integer can only be made with 2 negative integers or 1 positive and 1 negative integer.
<u>Answer:</u> The true statements are
for an endothermic reaction is positive, a combustion reaction is exothermic and when energy is transferred as heat from the system to the surroundings,
is negative.
<u>Explanation:</u>
There are 2 types of chemical reactions categorized into heat change:
- <u>Endothermic reactions:</u> These reactions are defined as the reactions in which energy is absorbed by the system from the surroundings. The
for these reactions is always positive. For Example: Changing of water into water vapor. - <u>Exothermic reactions:</u> These reactions are defined as the reactions in which energy is released by the system to the surroundings. The
for these reactions is always negative. For Example: Combustion reactions.
Combustion reactions are defined as the reactions in which a hydrocarbon reacts with oxygen gas to produce carbon dioxide and water. Heat is released during these reactions. Thus, it is considered as exothermic reactions.
Hence, the true statements are
for an endothermic reaction is positive, a combustion reaction is exothermic and when energy is transferred as heat from the system to the surroundings,
is negative.