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3 years ago

6

Looking at the Bohr models of atoms offer an explanation as to WHY the atomic size changes as it does for both periods and group

s.
Periods:
Groups:

1 answer:

andriy [413]3 years ago

5 0

Element 87 francium have the highest atomic size, so in short the closest element to francium have the high atomic size.

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Calculate the empirical formula for DCBN, given that the percent composition is 48.9%C, 1.76%H, 41.2%Cl, and 8.15%N.

sweet [91]

Answer:

empirical formula is C7H3NCl2

Explanation:

too much work too explain and im lazy

5 0

3 years ago

Ammonia, NH3, is a typical ingredient in household cleaners. It is produced through a combination reaction involving N2(g) and H

GalinKa [24]

The balanced chemical reaction is:

N2 + 3H2 = 2NH3

We are given the amount of hydrogen gas to be used in the reaction. This will be the starting point of the calculations.

24.0 mol H2 (2 mol NH3 / 3 mol H2 ) = 16 mol NH3

Therefore, ammonia produced from the reaction given is 16 moles.

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3 years ago

The experimental procedure has you wash your thermometer and dry it after you measure the temperature of naoh solution and befor

Rzqust [24]

<span>If you do not wash and dry the thermometer after every time you use it in this scenario, the temperature could be affected by the NaOH residue. This could make it so that your findings were inaccurate, so in order to be efficient, this precaution needs to be taken.</span>

6 0

3 years ago

Calculate the maximum volume (in mL) of 0.143 M HCl that each of the following antacid formulations would be expected to neutral

Nuetrik [128]

Answer:

a. The maximum volume of 0.143 M HCl required is 154.4 mL.

b. The maximum volume of 0.143 M HCl required is 135.7 mL.

Explanation:

a.

$Al(OH)_3+3HCl\rightarrow AlCl_3+3H_2O$

Mass of aluminum hydroxide = 350 mg = 0.350 g ( 1mg = 0.001 g)

Moles of aluminum hydroxide = $\frac{0.350 g}{78 g/mol}=0.004487 mol$

According to reaction ,3 moles of HCl neutralize 1 mole of aluminum hydroxide.Then 0.004487 mole of aluminum hydroxide will be neutralize by :

$\frac{3}{1}\times 0.004487 mol=0.01346 mol$ of HCl.

$Mg(OH)_2+2HCl\rightarrow MgCL_2+2H_2O$

Mass of magnesium hydroxide = 250 mg = 0.250 g ( 1mg = 0.001 g)

Moles of magnesium hydroxide = $\frac{0.250 g}{58 g/mol}=0.004310 mol$

According to reaction ,2 moles of HCl neutralize 1 mole of magnesium hydroxide.Then 0.004310 mole of magnesium hydroxide will be neutralize by :

$\frac{2}{1}\times 0.004310 mol=0.008621 mol$ of HCl.

Total moles of HCl required to neutralize both :

0.01346 mol + 0.008621 mol = 0.02208 mol

Molarity of the HCL solution = 0.143 M

Volume of the solution = V

$Molarity=\frac{\text{Total moles of HCl}{\text{Volume in Liter}}$

$V=\frac{0.02208 mol}{0.143 M}=0.1544 L$

1 L = 1000 mL

0.1544 L = 154.4 mL

The maximum volume of 0.143 M HCl required is 154.4 mL.

b.

$CaCO_3+2HCl\rightarrow CaCl_2+H_2O+CO_2$

Mass of calcium carbonate = 970mg = 0.970 g ( 1mg = 0.001 g)

Moles of calcium carbonate = $\frac{0.970 g}{100 g/mol}=0.00970 mol$

According to reaction ,2 moles of HCl neutralize 1 mole of calcium carbonate.Then 0.00970 mole of calcium carbonate will be neutralize by :

$\frac{2}{1}\times 0.00970 mol=0.0194 mol$ of HCl.

Total moles of HCl required to neutralize calcium carbonate : 0.0194 mol

Molarity of the HCL solution = 0.143 M

Volume of the solution = V

$Molarity=\frac{\text{Total moles of HCl}}{\text{Volume in Liter}}$

$V=\frac{0.0194 mol}{0.143 M}=0.1357 L$

1 L = 1000 mL

0.1357 L = 135.7 mL

The maximum volume of 0.143 M HCl required is 135.7 mL.

4 0

3 years ago

In 1869, mendeleev created a periodic table in which elements were ordered by weight and placed in groups based on their chemica

Tomtit [17]

Answer:

D

Explanation:

Mendeleev periodic table predicted the properties of undiscovered element like the eka-aluminium.

8 0

1 year ago