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:
The sun would appear to move more slowly across Mercury's sky.
Explanation:
This is because, the time it takes to do one spin or revolution on Mercury is 176 days (which is its period), whereas, the time it takes to do one spin or revolution on the Earth is 1 day.
Since the angular speed ω = 2π/T where T = period
So on Mercury, T' = 176days = 176 days × 24 hr/day × 60 min/hr × 60 s/min = 15,206,400 s
So, ω' = 2π/T'
= 2π/15,206,400 s
= 4.132 × 10⁻⁷ rad/s
So on Earth, T" = 1 day = 1 day × 24 hr/day × 60 min/hr × 60 s/min = 86,400 s
So, ω" = 2π/T"
= 2π/86,400 s
= 7.272 × 10⁻⁵ rad/s
Since ω' = 4.132 × 10⁻⁷ rad/s << ω" = 7.272 × 10⁻⁵ rad/s, <u>the sun would appear to move more slowly across Mercury's sky.</u>
Answer:
The most important resonance structure is 4 (attached picture). Its bon order is 
or 
.
Explanation:
A picture with 4 forms of the perchlorate structure is attached. The first structure has simple bonds. The second structure contains a double bond, the third structure has two double bonds and the fourth structure has three double bonds.
Formal charge = group number of the periodic table - number of bonds (number of bonding electrons / 2) - number of non-shared electrons (lone pairs)
The formal charges in the first structure is +3 in chlorine and -1 in oxygen.
The formal charges in the second structure is +2 in chlorine, -1 in oxygen and 0 in the double bond oxygen.
The formal charges in the third structure is +1 in chlorine, -1 in the single bond oxygens and 0 in the double bond oxygens.
The formal charges in the fourth structure is 0 in chlorine, -1 in the single bond oxygen and 0 in the double bond oxygens.
The most important resonance structure is given by:
- Most atoms have 0 formal charge.
- Lowest magnitude of formal charges.
- If there is a negative formal charge, it's on the most electronegative atom.
Hence, the fourth structure is the mosr important.
The bond order of the structure is:
Total number of bonds: 7
Total number of bond groups: 4
Bond order= 
Answer:
We need 17.2 L of Ca(OH)2
Explanation:
Step 1: Data given
Concentration of Ca(OH)2 = 1.45 M
Moles of H2SO4 = 25.0 moles
Step 2: The balanced equation
Ca(OH)2 + H2SO4 ⟶2H2O + CaSO4
Step 3: Calculate moles Ca(OH)2
For 1 mol Ca(OH)2 we need 1 mol H2SO4 to produce 2 moles H2O and 1 mol CaSO4
For 25.0 moles H2SO4 we'll need 25.0 moles Ca(OH)2 to produce 50 moles H2O and 25.0 moles CaSO4
Step 4: Calculate volume of Ca(OH)2
Volume Ca(OH)2 = moles Ca(OH)2 / concentration Ca(OH)2
Volume Ca(OH)2 = 25.0 moles / 1.45 M
Volume Ca(OH)2 = 17.2 L
We need 17.2 L of Ca(OH)2
Fluorine has the highest. Fluorine's electronegativity is 4.0
