All categories

3 years ago

What is the maximum volume of a 0.788 M CaCl2 solution that can be prepared using 85.3 g CaCl2?

1 answer:

5 0

The answer is 0.975 L

Volume = mol/Molarity

We have molarity (0.788 M) and we need mol and volume. Let's first calculate number of moles of CaCl2 in 85.3 g:

Molar mass of CaCl2 is sum of atomic masses of Ca and Cl:
Mr(CaCl2) = Ar(Ca) + 2Ar(Cl) = 40 + 2 * 35.45 = 40 + 70.9 = 110.9 g/mol

So, if 110.9 g are in 1 mol, 85.3 g will be in x mol:
110.9 g : 1 mole = 85.3 g : x
x = 85.3 g * 1 mole / 110.9
x = 0.769 moles

Now, calculate the volume:
V = 0.769/0.788
V = 0.975 L

You might be interested in

The half-life of a radioactive isotope is the amount of time it takes for a quantity of that isotope to decay to one half of its

Sedaia [141]

Radio active decay reactions follow first order rate kinetics.

a) The half life and decay constant for radio active decay reactions are related by the equation:

$t_{\frac{1}{2}} =$ $\frac{ln 2}{k}$

$t_{\frac{1}{2}} = \frac{0.693}{k}$

Where k is the decay constant

b) Finding out the decay constant for the decay of C-14 isotope:

$Decay constant (k) = \frac{0.693}{t_{\frac{1}{2}}}$

$k = \frac{0.693}{5230 years}$

$k = 1.325 * 10^{-4} yr^{-1}$

c) Finding the age of the sample :

35 % of the radiocarbon is present currently.

The first order rate equation is,

$[A] = [A_{0}]e^{-kt}$

$\frac{[A]}{[A_{0}]} = e^{-kt}$

$\frac{35}{100} = e^{-(1.325 *10^{-4})t}$

$ln(0.35) = -(1.325 *10^{-4})(t)$

t = 7923 years

Therefore, age of the sample is 7923 years.

3 0

3 years ago

A patient needs to be given exactly 1000 ml of a 5.0% (w/v) intravenous glucose solution. the stock solution is 55% (w/v). how m

LiRa [457]

The patient needs 1000 ml of 5% (w/v) glucose solution
i.e 1000 ml x 5 g/ 100 ml
where the stock solution is 55% (w/v) = 55 g / 100 ml
So, 1000 ml x 5 g / 100 ml = V (ml) x 55 g / 100 ml
V = 1000 x (5 / 100) / (55 / 100) = 5000 / 55 = 90.9 ml
∴ the patient needs 90.9 ml of 55% (w/v) glucose solution

6 0

3 years ago

2.22 (a) Briefly cite the main differences between ionic, covalent, and metallic bonding. (b) State the Pauli exclusion principl

Alja [10]

Answer: Ioniç bond is also called electrovalent bond. It involves the transfer of electrons from positively charged ions to negatively charged ions. covalent bond is a type of chemical bond that involves electrons sharing by atoms of a molecule in order to achieve a stable electronic configuration.. Metallic bond is a type of chemical bond that forms between metal atoms and it occurs when positive metal ions are attracted to a negatively charged electron that are not associated with a single atom. The differences can be seen in the definitions above.

Pauli exclusion principle states that electrons which are identical cannot have the same quantum state.

4 0

2 years ago

At standard ambient temperature and pressure (SATP), a gas has density of 1.5328g/L. What is the molar mass of the gas?

ahrayia [7]

The standard ambient temperature and pressure are

Temperature =298 K

Pressure = 1atm

The density of gas is 1.5328 g/L

density = mass of gas per unit volume

the ideal gas equation is

PV = nRT

P = pressure = 1 atm

V = volume

n = moles

R= gas constant = 0.0821 Latm/mol K

T = 298 K

moles = mass / molar mass

so we can write

n/V = density / molar mass

Putting values

$Pressure=\frac{nRT}{V}=\frac{massXRT}{VXmolarmass}$

$Pressure=\frac{densityXRT}{molarmass}$

$molarmass=\frac{densityXRT}{Pressure}=\frac{1.5328X0.0821X298}{1}=37.50$

Thus molar mass of gas is 37.50g/mol

6 0

3 years ago

Why do weak acid-weak base reactions not go to completion?

vladimir2022 [97]

Neither a weak acid nor a weak base has a strong tendency to transfer H+ ions that is why<span> weak acid-weak base reactions not go to completion.</span>

4 0

3 years ago

Read 2 more answers