<span>A chemical equation is balanced by changing or adding C. numbers in front of molecules, which are called coefficients.
For example:
O2 + 2 H2 ---> 2 H2O (number 2 is added to both sides in order to balance the equation)</span>
<span>Green ink is homogeneous.
please mark as brainliest
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<span>From the Born–Landé equation the lattice energy U ∝ (Z+ × Z-) / (r+ + r-) where Z+ and Z- are the charges on the cation and anion, respectively; r+ and r- are radii of the cation and anion, respectively.
The Z+×Z- term dominates. MgO has 2×2 (4) so it will have the higher U than Li2O Z+ × Z- = 2.
You only consider (r+ + r-) term when the Z+×Z- term is the same; smallest the (r+ + r-), the larger is the U.
U(MgO) = 3795 </span>kJ mol^-1
<span>U(Li2O) = 2799 kJ mol^-1
MgO has larger.
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Answer: 72.41% and 26.90% respectively.
Explanation:
At 60°C, you can dissolve 46.4g of acetanilide in 100mL of ethanol. If you lower the temperature, at 0°C, you can dissolve just 12.8g, which means (46.4g-12.8g)=33.6g of acetanilide must have precipitated from the solution.
We can calculate recovery as:
So the answer to the first question is 72.41%.
For the second part just use the same formula, the mass of the precipitate is the final mass minus the initial mass, (171mg-125mg)=46mg.
So the answer to the second question is 26.90%.
To write quantities in ordinary notation, you need to notice the power of the exponent.
If the power is positive, then you move the decimal point to the right by the number the power in exponent tells you.
If the power is negative, then you move the decimal point to the left by the number the power in exponent tells you.
We have:
3 x 10^-4 : the power of exponent is negative, therefore, we will move the decimal point 4 places to the left.
3 x 10^-4 = 0.0003 km
3 x 10^4 : he power of exponent is positive, therefore, we will move the decimal point 4 places to the right.
3 x 10^4 = 30000 km
