Answer:
1.89 g CaCO₃
Explanation:
You will have to use stoichiometry for this question. First, look at the chemical equation.
Na₂CO₃ + CaCl₂ ==> 2 NaCl + CaCO₃
From the above equation, you can see that for one mole of Na₂CO₃, you will produce one mole of CaCO₃. This means that however many moles of Na₂CO₃ you have in the beginning, you will have the same amount of moles of CaCO₃, theoretically speaking.
So, convert grams to moles. You should get 0.0189 mol Na₂CO₃. This means that you will get 0.0189 mol CaCO₃. I'm not sure what units you want the answer in, but I'm going to give it in grams. Convert moles to grams. Your answer should be 1.89 g.
Answer:
D
Explanation:
We know that the
reaction catalyzing power of a catalyst ∝ surface area exposed by it
Given
volume V1= 10 cm^3
⇒
hence r= 1.545 cm
also, surface area S1= 
now when the sphere is broken down into 8 smaller spheres
S2= 8×4πr'^2
now, equating V1 and V2 ( as the volume must remain same )

and solving we get
r'= r/2
therefore, S2=
S2=
S2= 2S1
hence the correct answer is
. The second run has twice the surface area.
The elements that form anions will have the electronic configuration similar to the noble gas that is in their period and those that form cations will have a configuration similar to that of the noble gas in the previous period.
He: Be
Ne: F, Al
Ar: Ca, P
Kr: Rb, Se
Answer:
Moon rocks contain few volatile substances (e.g. water), which implies extra baking of the lunar surface relative to that of Earth. The relative abundance of oxygen isotopes on Earth and on the Moon are identical, which suggests that the Earth and Moon formed at the same distance from the Sun.
Explanation: