Which of the following has the largest atomic radius: calcium, beryllium, barium, and strontium

HELP ASAP <br><br>GIVING BRIANALST TO THE FRIST TO ANSWER

Kisachek [45]

Answer:

yes the ones u chose are correct.

Explanation:

8 0

3 years ago

Select all of the answers that apply.

saveliy_v [14]

A meteorologist predicts fog in the morning over lakes and river bottoms because of the atmospheric conditions and their interactions with the <span>hydrosphere. The hydrosphere is the region on the Earth's surface where the total water on the planet is found. The hydrosphere can be in the form of liquid, vapor, or ice.</span>

5 0

3 years ago

Where the oxygen comes from the air (21% O2 and 79% N2). If oxygen is fed from air in excess of the stoichiometric amount requir

guajiro [1.7K]

Answer:

$y_{O2} =4.3$ %

Explanation:

The ethanol combustion reaction is:

$C_{2}H_{5} OH+3O_{2}$ → $2CO_{2}+3H_{2}O$

If we had the amount (x moles) of ethanol, we would calculate the oxygen moles required:

$x*1.10(excess)*\frac{3 O_{2}moles }{etOHmole}$

Dividing the previous equation by x:

$1.10(excess)*\frac{3 O_{2}moles}{etOHmole}=3.30\frac{O_{2}moles}{etOHmole}$

We would need 3.30 oxygen moles per ethanol mole.

Then we apply the composition relation between O2 and N2 in the feed air:

$3.30(O_{2} moles)*\frac{0.79(N_{2} moles)}{0.21(O_{2} moles)}=121.414 (N_{2} moles )$

Then calculate the oxygen moles number leaving the reactor, considering that 0.85 ethanol moles react and the stoichiometry of the reaction:

$3.30(O_{2} moles)-0.85(etOHmoles)*\frac{3(O_{2} moles)}{1(etOHmoles)} =0.75O_{2} moles$

Calculate the number of moles of CO2 and water considering the same:

$0.85(etOHmoles)*\frac{3(H_{2}Omoles)}{1(etOHmoles)}=2.55(H_{2}Omoles)$

$0.85(etOHmoles)*\frac{2(CO_{2}moles)}{1(etOHmoles)}=1.7(CO_{2}moles)$

The total number of moles at the reactor output would be:

$N=1.7(CO2)+12.414(N2)+2.55(H2O)+0.75(O2)\\ N=17.414(Dry-air-moles)$

So, the oxygen mole fraction would be:

$y_{O_{2}}=\frac{0.75}{17.414}=0.0430=4.3$ %

6 0

3 years ago

What mass of lead (II) chloride is produced when 200.0 mL of a 0.250 M solution of sodium chloride is mixed with 200.0 mL of a 0

kow [346]

Answer:

Option d. 6.95 g

Explanation:

First of all, we state the reaction:

2NaCl + Pb(NO₃)₂ → PbCl₂ + 2NaNO₃

We determine the moles of each reactant, to state the limiting

Firstly we convert volume frm mL to L

0.200 L . 0.250M = 0.05 moles of NaCl

0.200L . 0.250M = 0.05 moles of Pb(NO₃)₂

Acording to stoichiometry we know that relation is 1:2, so the limiting reagent is the NaCl.

For 1 mol of Pb(NO₃)₂ I need 2 moles of NaCl

For 0.05 moles of Pb(NO₃)₂ I would need, the double → 0.1 moles

(We only have, 0.05 moles of NaCl)

Stoichiometry to the formed product is 2:1

From 2 moles of NaCl I produce 1 mol of PbCl₂

From 0.05 moles I would produce, the half → 0.025 moles

Let's convert the moles to mass → 0.025 mol . 278.1 g / 1mol = 6.95 g

8 0

3 years ago

Is each of these statements true? If not, explain why.(g) The rate of a reaction increases as the reaction proceeds.

Elina [12.6K]

The rate of a reaction rises as it progresses. The answer is false

<h3>What causes a reaction's rate to increase?</h3>

Generally speaking, raising the temperature of the reaction system, raising the concentration of a reactant in solution, and raising the surface area of a solid reactant will all raise the rate of a reaction. A catalyst can be added to the reaction mixture to speed up a process as well.

As reactants are used up, reactions often get slower with time. Catalysts are substances that, when added to a process, speed it up even if they are not themselves reactants.

learn more about reaction's rate refer

brainly.com/question/7578129

#SPJ4

7 0

2 years ago