Answer : The correct option is A.
Explanation :
Law of conservation of mass : In the chemical reaction, the mass of reactant must be equal to the mass of product.
A. 
The mass of reactant side = ![2C_4H_{10}+2Cl_2+12O_2=[8(12)+20(1)]+4(35.5)+24(16)=642g](https://tex.z-dn.net/?f=2C_4H_%7B10%7D%2B2Cl_2%2B12O_2%3D%5B8%2812%29%2B20%281%29%5D%2B4%2835.5%29%2B24%2816%29%3D642g)
The mass of product side = 
This means, the mass of product is equal to the mass of reactant. The mass remains conserved and obeys the law of conservation of mass.
The reaction B, C, D, E does not obey the law of conservation of mass.
Therefore, Only reaction A obey the law of conservation of mass.
Cobalt(II) has a charge of 2+
Phosphate has a charge of 3-
Because it's an ionic compound, you will need to take the charge and make them subscripts.
The formula for cobalt(II) phosphate is
Co₃(PO₄)₂
Your answer is
The concentration in mol L-l (M) = 0.717
<h3>Further explanation</h3>
Given
12% solution of tetrahydrate magnesium chloride (MgCl₂)
Required
The concentration
Solution
Tetrahydrate magnesium chloride (MgCl₂)⇒MgCl₂.4H₂O
MW = Ar Mg+2. Ar Cl+8. Ar H + 4. Ar O
MW=24.31 + 2 x 35.45 + 8 x 1.01 + 4 x 16
MW=24.31+70.9+8.08+64
MW=167.29 g/mol
12% solution = 12 % m/v = 12 g in 100 ml solution
For 1 L solution :
The concentration in g/L = 120 g/L
Convert grams to moles :
Answer:
The best answer choice is likely D.
Explanation:
Warm fronts are almost always associated with humid weather. We can eliminate options B and C because they don't really make much sense.
Cold fronts are associated with heavy thunderstorms and rain, so that eliminates option A.
We are left with option D, although I would have worded it differently.
Sorry you have to suffer through Edge ; I'm going through it too :)
