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dimulka [17.4K]

1 year ago

12

Rhett is solving the quadratic equation 0= x2 – 2x – 3 using the quadratic formula. Which shows the correct substitution of the

values a, b, and c into the quadratic formula?

1 answer:

bekas [8.4K]1 year ago

8 0

The correct values I believe would be a=1 b=-2 and c=-3.

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Identify the most and the least acidic compound in each of the following sets.

il63 [147K]

Answer:

See explanation

Explanation:

Our answer options for this question are:

a. 2-chlorobutanoic acid:_______ 2-chlorobutanoic acid:_______ 3-chlorobutanoic acid:______.

b. 2,4-dinitrobenzoic acid:______ p-nitrobenzoic acid:______ p-bromobenzoic acid:_______.

c. p-cyanobenzoic acid:________ benzoic acid:_______ p-aminobenzoic acid:______

We have to check each set of molecules

<u>a. 2-chlorobutanoic acid,</u> <u>3-chlorobutanoic acid</u>

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In this case, the difference between these molecules is the position of "Cl". If the chlorine atom is closer to the acid group, we will have a higher inductive effect. So, the bond O-H would be weaker and we will have more acidity. So, the molecule with more acidity is <u>2-chlorobutanoic acid</u> and the less acidic would be <u>3-chlorobutanoic acid.</u>

<u />

<u>b. 2,4-dinitrobenzoic acid,</u> <u>p-nitrobenzoic acid,</u> <u>p-bromobenzoic acid</u>

<u />

In this case, we have several structural differences. In all the structure, we have deactivating groups ( $Br$ and $NO_2$ ). If we have a deactivating group the acidity will increase. In the case of "Br", we have a weak deactivating, so, this will be the less acidic one (<u>p-bromobenzoic acid)</u>

in <u>2,4-dinitrobenzoic acid</u> we have two deactivating groups, therefore, this would be the most acid compound.

<u>c. p-cyanobenzoic acid</u>, <u>benzoic acid</u>, <u>p-aminobenzoic acid</u>

On these molecules, we have several structural differences. In <u>p-cyanobenzoic acid</u> we have a deactivating group, therefore in this molecule we will have more acidity. In the <u>p-aminobenzoic acid,</u> we have an activating group, so, this would be the less acidic compound.

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See figure 1

I hope it helps!

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3 0

2 years ago

A sample of copper with a mass of 63.5g contains 6.02 x10^23 atoms calculate the mass of an average copper atom

m_a_m_a [10]

Answer:

The mass of an average copper atom is $1.0548\times 10^{-22}\ g$

Explanation:

Given:

The total mass of copper atoms, $m = 63.5\ g$

Number of atoms, $N=6.02\times 10^{23}$

Now, we are asked to find the mass of 1 copper atom.

We use unitary method to find the mass of 1 copper atom.

Mass of $N$ atoms = m

∴ Mass of 1 atom = $\frac{m}{N}$

Plug in 63.5 for 'm', $6.02\times 10^{23}$ for 'N' and simply.

Mass of 1 atom = $\dfrac{63.5}{6.02\times 10^{23}}=1.0548\times 10^{-22}\ g$

Therefore, the mass of an average copper atom is $1.0548\times 10^{-22}\ g$

5 0

2 years ago

The electron configuration of an element is 1s22s22p4. Describe what most likely happens when two atoms of this element move tow

ahrayia [7]

When two atoms of this element move towards each other, they will combine in a covalent bond to form a diatomic molecule.

Looking at the electron configuration of the atoms; 1s2 2s2 2p4, we can see that these are atoms of elements in group 16. The elements in group 16 has a general outer electronic configuration of ns2np4. They have a valency of 2.

When two atoms of this element approach each other, they will combine in a covalent bond to form a compound. If this element is depicted as X, the compound formed is X2.

Learn more: brainly.com/question/1527403

5 0

1 year ago

9 The Haber process is a reversible reaction. N2(g) + 3H2(g) 2NH3(g) The reaction has a 30% yield of ammonia. Which volume of am

Illusion [34]

Answer: 3.36 L of ammonia gas

Explanation:

The balanced chemical reaction is:

$N_2(g)+3H_2(g)\rightarrow 2NH_3(g)$

According to stoichiometry :

3 moles of $H_2$ produce = 2 moles of $NH_3$

Thus 0.75 moles of $H_2$ will producee= $\frac{2}{3}\times 0.75=0.50moles$ of $NH_3$

But as percent yield is 30 %, amount of ammonia produced = $\frac{30}{100}\times 0.50moles=0.15moles$

According to ideal gas equation:

$PV=nRT$

P = pressure = 1 atm

V = Volume = ?

n = number of moles = 0.15

R = gas constant = $0.0821Latm/Kmol$

T =temperature = $273K$

$V=\frac{nRT}{P}$

$V=\frac{0.15\times 0.0820 L atm/K mol\times 273K}{1atm}=3.36L$

Thus 3.36 L of ammonia gas is obtained by reacting 0.75 moles of hydrogen with excess nitrogen.

3 0

1 year ago

Use the periodic table to select which type of bond is present and which of the listed properties is most likely for each substa

hoa [83]

Answer:

A :metallic

B :conducts electricity as a solid

C :covalent

D :does not conduct electricity

Explanation:

4 0

1 year ago