The complete question is found on the image attached.
Answer:
a) Rb= +1, Br= -1
b)Bromide and rubidium ions are related to krypton
c) C
Explanation:
Rubidium is found in group 1 with a charge of +1. Bromine is found in group 17 with a charge of -1. Both species have the same configuration as krypton. The ionic sizes of the ions are a very similar to each other Rb+ is 166 while Be is 167.
This RbBr is an ionic compound.
The trick for this problem is to understand atomic mass: the fact that different atoms have different masses. What we need to do is add up all the atomic masses of the compound and work out the ratio of mass of water to the mass of sodium carbonate. Atomic masses are often given for each atom in the periodic table, but you can look them up on google too.
You can do this by adding up individual atoms for each molecule, or you can shortcut and lookup the molar mass of the compound (i.e.the task already done for you).
The molar mass of water is 18.01g/mole so for 10 moles of water we have a mass of 180.1g.
The molar mass of sodium carbonate is 106g/mole (google).
So the total mass of the sodium carbonate decahydrate compound is 180.1+106 = 286.1g, of which water would make up 180.1g, so the percentage of water is is 180.1/286.1 = 0.629, so we can round this to 63%
:)
Answer:
Explanation:
First, find the molar mass of calcium (Ca). This can be found on the Periodic Table.
Next, find the number of moles.
Avogadro's Number tells us the number of atoms in one mole.
Therefore, there are 6.023*10²³ atoms in 1 mole.
We have 6.023*10²³ atoms of calcium, so it must also be 1 mole of calcium.
Finally, find the mass. Set up a proportion using the molar mass of calcium.
Multiply. The moles (mol Ca) will cancel.
There are <u>40.08 grams </u>in 6.023*10²³ atoms of calcium.
Integer i think but i not sure
528 calories or 2207.04 joules.
Q=MCT
Q=(6g)(1.0cal/g°C)(88°C)
Q= 528 calories
Q=MCT
Q=(6g)(4.18joules/g°C)(88°C)
Q= 2207.04 joules
