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3 years ago

Which best describes a compound such as sodium

Chemistry

1 answer:

tresset_1 [31]3 years ago

3 0

<span>a pure substance that can be separated into different elements by chemical means</span>

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Why do you think the molarity relationship is so important to the chemist?

Oksana_A [137]

There are two big advantages of using molarity to express concentration. The first advantage is that it's easy and convenient to use because the solute may be measured in grams, converted into moles, and mixed with a volume.

The second advantage is that the sum of the molar concentrations is the total molar concentration. This permits calculations of density and ionic strength

5 0

3 years ago

The equilibrium constant for the formation of ammonia from nitrogen and hydrogen is 1.6 × 102. what is the form of the equilibri

Nimfa-mama [501]

Answer: The expression for equilibrium constant is $\frac{[NH_3]^2}{[H_2]^3[N_2]}$

Explanation: Equilibrium constant is the expression which relates the concentration of products and reactants preset at equilibrium at constant temperature. It is represented as $k_c$

For a general reaction:

$aA+bB\rightleftharpoons cC+dD$

The equilibrium constant is written as:

$k_c=\frac{[C]^c[D]^d}{[A]^a[B]^b}$

Chemical reaction for the formation of ammonia is:

$N_2+3H_3\rightleftharpoons 2NH_3$

$k_c=1.6\times 10^2$

Expression for $k_c$ is:

$k_c=\frac{[NH_3]^2}{[H_2]^3[N_2]}$

$1.6\times 10^2=\frac{[NH_3]^2}{[H_2]^3[N_2]}$

8 0

3 years ago

You have just isolated a new radioactive element. If you can determine its half-life, you will win the Nobel Prize in physics. Y

lbvjy [14]

Answer: 2.58 days

Explanation:

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 = ?

t = age of sample = 6 days

a = initial amount of the reactant = 1 g

a - x = amount left after decay process = 0.2 g

a) to find the rate constant

$6=\frac{2.303}{k}\log\frac{1.0}{0.2}$

$k=\frac{2.303}{6}\log\frac{1.0}{0.2}$

$k=0.268days^{-1}$

b) for completion of half life:

Half life is the amount of time taken by a radioactive material to decay to half of its original value.

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

$t_{\frac{1}{2}}=\frac{0.693}{0.268}=2.58days$

The half life is 2.58 days

3 0

3 years ago

Encountering problems during separation/purification is a very common issue in organic synthesis, but these steps are crucial to

Rus_ich [418]

True is the correct answer! your welcome! :)

8 0

3 years ago

Using the principles of VSEPR theory, you can predict the geometry around any atom in any molecule, no matter how complex. Enant

Kaylis [27]

Explanation:

The O atom is sp3 in a water molecule, with two sigma bonds and two lone pairs of electrons like that in water. The steric integer is thus 4, and its structure is tetrahedral.

The C atom is sp hybridised into two identical bonds and two identical bonds in acetylene.

The steric integer is therefore 2 because only sigma bonds are engaged in deciding hybridization, and its structure is linear.

The C atom is sp2 hybridised in ethene with single pi bond and three sigma identical bonds.

Thus the steric integer is 3, and its structure is planar trigonal.

The C atom is sp2 hybridized in ethene, with one pi bond and three sigma identical bonds.

The steric integer would therefore be 3 and its structure is planar trigonal.

The O atom is sp3 in a water molecule with two bond pairs and two lone pairs of electrons like that. The steric integer is thus 4, and its structure is tetrahedral.

The C atom is sp3 in a methane ring, with 4 bond pairs and no solitary pairs of electrons like that. The steric integer is thus 4, and its structure is tetrahedral.

6 0

3 years ago