The mass of calcium hydroxide that is formed when 10.0 g of CaO reacts with 10.0 g of water is 13.024 grams
calculation
from the equation
CaO + H2O → Ca(OH)2,
1 moles of CaO reacted with 1 moles of H2O to form 1 moles of Ca(OH)2
find the moles of each reactant
moles=mass/molar mass
moles of CaO= 10 g/56 g/mol=0.179 moles
moles of H2O = 10 g/18 g/mol 0.556 moles
CaO is the limiting reagent therefore by use of mole ratio of CaO:Ca(OH)2 which is 1:1 moles of Ca(OH)2 is = 0.179 moles
mass= moles x molar mass
= 0.176 moles x 74 g/mol = 13.024 grams
Answer:
Just say I wonder why teachers give homework :/
Explanation:
Answer:
A neutral atom have equal number of proton and electron. In other words we can say that negative and positive charges are equal in magnitude and cancel the each other and atom become neutral.
Explanation:
An atom consist of electron, protons and neutrons. Protons and neutrons are present with in nucleus while the electrons are present out side the nucleus.
All these three subatomic particles construct an atom. A neutral atom have equal number of proton and electron. In other words we can say that negative and positive charges are equal in magnitude and cancel the each other and atom become neutral. For example if neutral atom has 6 protons than it must have 6 electrons. The sum of neutrons and protons is the mass number of an atom while the number of protons are number of electrons is the atomic number of an atom.
For example
The carbon have six protons and six neutrons so its atomic mass is 12 amu and atomic number is six.
Answer:
230
Th
90
Explanation:
The left side shows the element uranium with mass number 234 (superscript to the left of ths symbol) and atomic mass 92 (subscript to the left of the symbol).
So, you have to find the mass number and atomic numbers missing on the right side which added to those shown for the helium atom reach 234 and 92.
This the the mathematics:
1) Mass number of U - mass number of He = 234 - 4 = 230 ⇒ the mass number of the missing element is 230.
2) atomic number of U - atomic number of He = 92 - 2 = 90 ⇒ the atomic number of the missing element is 90.
Now, you use the atomic mass to identify the element. You do it by simply searching in a periodic table. There you find that the atomic number 90 corresponds to thorium, whose symbol is Th.
Now you have that the product that completes the right side of the decay equation is:
230
Th
90
