HELPPPP ASAPP 10 POINTS

How many liters of 0.305 M K3PO4 solution are necessary to completely react with 187 mL of 0.0184 M NiCl2 according to the balan

Mashutka [201]

Answer:

6.55 mL of K₃PO₄ are required

Explanation:

We need to propose the reaction, in order to begin:

2K₃PO₄ (aq) + 3NiCl₂(aq) → Ni₃(PO₄)₂ (s) ↓ + 6KCl (aq)

Molarity = mol/L (Moles of solute that are contained in 1 L of solution.)

M = mol / volume(L). Let's find out the moles of chloride:

- We first convert the volume from mL to L → 187 mL . 1L / 1000mL = 0.187L

0.0184 M . 0.187L = 0.00344 moles of NiCl₂

Ratio is 3:2. Let's propose this rule of three:

3 moles of chloride react with 2 moles of phosphate

Then, 0.00344 moles of NiCl₂ will react with (0.00344 . 2) /3 = 0.00229 moles of K₃PO₄

M = mol / volume(L) → Volume(L) = mol/M

Volume(L) = 0.00229 mol / 0.350 M = 6.55×10⁻³L

We convert the volume from L to mL → 6.55×10⁻³L . 1000mL /1L = 6.55 mL

5 0

3 years ago

Describe the electrical charges of the particles in atoms

vodka [1.7K]

Answer:

Atom consist of three particles proton , electron and neutron.

electrical charge on electron= -1.6022 × 10∧-19 C

electrical charge on proton= +1.6022 × 10∧-19 C

electrical charge on neutron= 0

Explanation:

Atoms are the fundamental unit of matter. Every thing in the universe that occupy space and have mass is called matter. we can say that every matter is composed of atoms. while the atom is composed of subatomic particles called electron proton and neutron.

Electron:

The electron is subatomic particle that revolve around outside the nucleus and has negligible mass. It has a negative charge.

Symbol = e-

Mass= 9.10938356×10-31 Kg

electrical charge on electron= -1.6022 × 10∧-19 C

It was discovered by j. j. Thomson in 1897 during the study of cathode ray properties.

Proton and Neutron:

An atom consist of positively charged central core (nucleus) that is made up of Proton and neutron. Proton has positive charge while neutron is electrically neutral. Proton is discovered by Rutherford while neutron is discovered by James Chadwick in 1932.

Symbol of proton= P+

electrical charge on proton= +1.6022 × 10∧-19 C

Mass of proton=1.672623×10-27 Kg

Symbol of neutron= n0

Mass of neutron=1.674929×10-27 Kg

electrical charge on neutron= 0

All these three subatomic particles construct an atom. A neutral atom have equal number of proton and electron. In other words we can say that negative and positive charges are equal in magnitude and cancel the each other. For example if neutral atom has 6 protons than it must have 6 electrons.

4 0

3 years ago

Strotium−90, a radioactive isotope, is a major product of an atomic bomb explosion. It has a half-life of 28.1 yr. (a) Calculate

Bess [88]

Answer :

(a) The first-order rate constant for the nuclear decay is, $0.0247\text{ years}^{-1}$

(b) The fraction of 90-Sr that remains after 10 half-lives is, $\frac{a_o}{1024}$

(c) The time passed in years is, 127.4 years.

Explanation :

Part (a) :

Half-life = 28.1 years

First we have to calculate the rate constant, we use the formula :

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

$k=\frac{0.693}{28.1\text{ years}}$

$k=0.0247\text{ years}^{-1}$

Thus, the first-order rate constant for the nuclear decay is, $0.0247\text{ years}^{-1}$

Part (b) :

Now we have to calculate the fraction of 90-Sr that remains after 10 half-lives.

Formula used :

$a=\frac{a_o}{2^n}$

where,

a = amount of reactant left after n-half lives

$a_o$ = Initial amount of the reactant

n = number of half lives = 10

Now put all the given values in the above formula, we get:

$a=\frac{a_o}{2^{10}}$

$a=\frac{a_o}{1024}$

Thus, the fraction of 90-Sr that remains after 10 half-lives is, $\frac{a_o}{1024}$

Part (c) :

Now we have to calculate the time passed.

Expression for rate law for first order kinetics is given by:

$t=\frac{2.303}{k}\log\frac{a}{a-x}$

where,

k = rate constant = $0.0247\text{ years}^{-1}$

t = time passed by the sample = ?

a = let initial amount of the reactant = 100

a - x = amount left after decay process = 100 - 95.7 = 4.3

Now put all the given values in above equation, we get

$t=\frac{2.303}{0.0247}\log\frac{100}{4.3}$

$t=127.4\text{ years}$

Therefore, the time passed in years is, 127.4 years.

6 0

3 years ago

Which observation tool is the most advanced?

aalyn [17]

Answer

B. Hubble Space Telescope

Explanation

The Hubble Space Telescope From NASA that was launched in 1990 is the most advanced one that has been observing the Earth orbit for more than 18 years .Its wavelengths are in the visible, UV , and Near-IR and it produces images that are clear and stunning.

7 0

3 years ago

Read 2 more answers

How many hydrogen atoms are in 3.90 mol of ammonium sulfide?

lozanna [386]

Answer:

First, the number of ammonium sulfide molecules should be calculated:

N = NA × n,

where NA - the Avogadro number, n - number of moles.

N (ammonium sulfide) = 6.022 × 1023 × 8.5 mol = 51.187 × 1023.

The moelcular formula of ammonium sulfide is (NH4)2S. It means that each molecule contains 8 hydrogen atoms.

As a result, 8.5 mol of (NH4)2S contain:

51.187 × 1023 × 8 = 41 × 1024 hydrogen atoms.

Answer: 41 × 1024 hydrogen atoms

8 0

3 years ago