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2 years ago

What is the hydroxide ion concentration of the lake described in question 3?

1 answer:

3 0

The hydroxide concentration is written as [OH-]. A useful equation is that pH + pOH = 14. Since the pH is 4, the pOH must be 10. To get [OH-], again take the neg. anti-log of both sides: - anti log (pOH-) = - antilog(10) ---> [OH-]=1 x 10^-10 M or 1 x 10^-10 moles [OH-] per liter solution (in this case, lake).
The hydroxide ion concentration describe in question 3 is 10-10 M

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At a temperature of __________ °c, 0.444 mol of co gas occupies 11.8 l at 889 torr.

Novay_Z [31]

<span>ideal gas law is: PV = nRT P = pressure (torr) = 889 torr V = volume (Liters) = 11.8 L n = moles of gas = 0.444 mol R = gas constant = 62.4 (L * torr / mol * k) solve for T (in kelvin) T = PV/nR T = (889*11.8)/(.444*62.4) T = 378.6 K convert to C (subtract 273) T = 105.6 deg C</span>

3 0

2 years ago

Read 2 more answers

How many total ions are present in 347g of cacl2?

vladimir1956 [14]

In 1 mole of $CaCl_{2}$ , there are 3 moles of ions, 1 mole of Ca^{2+} and 2 mole of $Cl^{-1}$ .

$CaCl_{2}\rightarrow Ca^{2+}+2Cl^{-}$

Molar mass of $CaCl_{2}$ is 110.98 g/mol. Calculating number of moles from given mass as follows:

$n=\frac{m}{M}=\frac{347 g}{110.98 g/mol}=3.12 mol$

Thus, number of moles of ions will be $3\times 3.12 mol=9.38 mol$ .

Since, 1 mole of any substance has $6.023\times 10^{23}$ units of that substance where $6.023\times 10^{23}$ is Avogadro's number.

Thus, 9.38 mol of ions will have $9.38\times 6.023\times 10^{23}=5.65\times 10^{24}$ number of ions.

Therefore, total number of ions in 347 g of $CaCl_{2}$ is $5.65\times 10^{24}$ .

8 0

2 years ago

SnO2 is reduced by carbon according to this reaction: SnO2 + C ???? Sn + CO2. How many liters of CO2 are produced if 300.0 grams

andrew-mc [135]

Explanation:

The given reaction is as follows.

$SnO_{2} + C \rightarrow Sn + O_{2}$

a). Molar mass of $SnO_{2}$ is [(mass of Sn) + (2 × mass of O)].

Therefore, molar mass of $SnO_{2}$ = (118.7 + 2 × 16) g/mol = 150.7 g/mol

Since, it is known that number of moles equal mass divided by molar mass. So, moles of Sn will be calculated as follows.

No. of moles = $\frac{mass}{molar mass of SnO_{2}}$

= $\frac{300 g}{150.7 g/mol}$

= 2.53 mol

As it is given that 1 mole of $SnO_{2}$ produces 1 moles of Sn and 1 moles of $CO_{2}$ . Hence, 2.53 moles of $SnO_{2}$ will also produce 2.53 moles of Sn and 2.53 moles of $CO_{2}$ .

Volume of 1 mole of $CO_{2}$ at STP is 22.4 L. Therefore, volume of 2.53 moles of $CO_{2}$ will be calculated as follows.

2.53 × 22.5 L = 56.67 L

Hence, 56.67 L of $CO_{2}$ are produced if 300.0 grams of tin are produced at STP.

b). Mass of tin is given as 1800.0 g. So, number of moles will be calculated as follows.

No. of moles = $\frac{mass}{molar mass of tin}$

= $\frac{1800.0 g}{118.7 g/mol}$

= 15.2 moles

As 15.2 moles of $SnO_{2}$ produces 15.2 moles of Sn. Therefore, weight of $SnO_{2}$ will be calculated as follows.

Mass = no. of moles × molar mass of $SnO_{2}$

= 15.2 moles × 150.7 g/mol

= 2290.64 g

Hence, 2290.64 grams of $SnO_{2}$ are required to produce 1800.0 grams of tin.

c). Mass of carbon given is 100.0 grams.

No. of moles = $\frac{mass}{molar mass of carbon}$

= $\frac{100 g}{12 g/mol}$

= 8.33 moles

As, 1 mole of carbon is produced by 1 mole of tin. So, 8.33 mole of carbon will be produced by 8.33 moles of tin.

Therefore, calculate mass of tin produced as follows.

Mass = no. of moles × molar mass of Sn

= 8.33 moles × 118.7 g/mol

= 988.8 g

Hence, 988.8 grams of tin will be produced per 100 grams of carbon used.

8 0

2 years ago

Which substance is present in the smallest proportion in a solution?

blagie [28]

The substance present in the smallest amount in a solution is the solute; it is the substance that is dissolved. While the solvent is the substance present in the largest amount in a solution, it is the substance that does the dissolving. A solution is a homogeneous mixture formed when one substance dissolves in another.

7 0

2 years ago

In the PhET simulation, make sure that the checkbox Stable/Unstable in the bottom right is checked. Using the PhET simulation as

lord [1]

Answer:

kindly check the EXPLANATION SECTION

Explanation:

In order to be able to answer this question one has to consider the neutron proton ratio. Considering this ratio will allow us to determine the stability of a nuclei. The most important rule that helps us in determination of stability is that when the Neutron- Proton ratio of any nuclei ranges from to 1 to 1.5, then we say the nuclei is STABLE.

Also, we need to understand that when the Neutron- Proton ratio is LESS THAN 1 or GREATER THYAN 1.5, then we say the nuclei is UNSTABLE.

So, let us check which is stable and which is unstable:

a. 4 protons and 5 neutrons = Neutron- proton ratio = N/P = 5/4= stable.

b. 7 protons and 7 neutrons = Neutron- proton ratio = N/P = 7/7= 1 = stable.

c. 2 protons and 3 neutrons = Neutron- proton ratio = N/P = 3/5 =0.6 =unstable.

d. 3 protons and 0 neutrons = Neutron- proton ratio = N/P = 0/3= 0= unstable.

e. 6 protons and 5 neutrons = Neutron- proton ratio = N/P = 5/6= 0.83 = unstable.

f. 9 protons and 9 neutrons = Neutron- proton ratio = N/P = 9/9 = 1 = stable.

g. 8 protons and 7 neutrons = Neutron- proton ratio = N/P = 7/8 =0.875 = unstable.

h. 1 proton and 0 neutrons = Neutron- proton ratio = N/P = 0/1 =0 = unstable

6 0

2 years ago