Answer:
There should be one lithium, not two.
Explanation:
Lithium reacts with hydrogen at about 750°C to yield lithium hydride (LiH). LiH is white and powdery in appearance. It releases hydrogen gas when it reacts with water.
The correct formula for Lithium hydride is LiH and not Li2H because both lithium and hydrogen are univalent. Lithium has a valency of +1 while hydrogen has a valency of -1 in lithium hydride. Hydrides are formed between hydrogen and highly electro positive metals. In hydrides, hydrogen is forced to accept an electron from the highly electro positive metal.
Answer: D=4.35g/L
Explanation:
The formula for density is . M is mass in grams and V is volume in liters.
Since we are give pressure and temperature, we can use the ideal gas law to find moles/volume. FInding moles/volume would give us the base for density. All we would have to do is convert moles to grams.
Ideal Gas Law: PV=nRT
Now that we have moles, we can use molar mass of chlorine gas to find grams.
With our grams, we can find our density.
We need correct significant figures so our density is:
Answer:
True
Explanation:
The vertical columns on the periodic table are called groups or families because of their similar chemical behavior. All the members of a family of elements have the same number of valence electrons and similar chemical properties. The horizontal rows on the periodic table are called periods.
Answer : The concentration of are 0.127 ppm, 0.127 ppm and 0.254 ppm respectively.
Explanation : Given,
Mass of =
Volume of solution = 2.25 L
First we have to calculate the concentration in terms of g/L.
conversion used :
As we know that,
1 mg/L = 1 ppm
0.127 mg/L = 0.127 ppm
So, the concentration will be 0.127 ppm.
The concentration of in ppm is, 0.127 ppm.
Now we have to calculate the concentration of and .
We assume that, dissociates 100 % in the solution then the balanced reaction will be:
From the reaction we conclude that the mole ratio of is, 1 : 1 : 2. So,
The concentration of = 0.127 ppm
The concentration of = 2 × 0.127 ppm = 0.254 ppm