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3 years ago

Choose all the answers that apply.

Chemistry

2 answers:

Tresset [83]3 years ago

5 0

<h3>Answer:</h3>

#a.2H2 + O2 → 2H2O

#b. 2S + 3O2 → 2SO3

#d. 2K + 2H2O → H2 + 2KOH

<h3>Explanation:</h3>

A balanced chemical equation is one that has equal number of atoms of each element on both sides of the equation.

In this case;

2H2 + O2 → 2H2O - is balanced since it has, 4 hydrogen atoms and 2 oxygen atoms on either sides of the equation.
2S + 3O2 → 2SO3, is balanced. It has 2 sulfur atoms and 6 oxygen atoms on both side of the equation.
2K + 2H2O → H2 + 2KOH, is balanced , 2 potassium atoms, 4 hydrogen atoms and 2 oxygen atoms on both side of the equation.

On the other hand, the equations that are not balanced include;

Li + Cl2 → LiCl
2Fe + Cu(NO3)2 → 2Cu + Fe(NO3)2

This is because the number of atoms of each element is not equal on both side of the equation/

nordsb [41]3 years ago

5 0

Answer: A B D

Explanation:

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As a chemist for an agricultural products company, you have just developed a new herbicide,"Herbigon," that you think has the po

Ganezh [65]

Answer:

pH = 2.03

Explanation:

The pH can be calculated using the following equation:

$pH = -log [H_{3}O^{+}]$ (1)

The concentration of H₃O⁺ is calculated using the dissociation constant of the next reaction:

CH₃COOH + H₂O ⇄ CH₃COO⁻ + H₃O⁺

1.00 M

$K_{a} = \frac{[CH_{3}COO^{-}][H_{3}O^{+}]}{[CH_{3}COOH]}$

Solving the above equation for H₃O⁺, we have:

$[H_{3}O^{+}] = \frac{Ka*[CH_{3}COOH]}{[CH_{3}COO^{-}]}$ (2)

The dissociation constant is equal to:

$pKa = -log(Ka) \rightarrow Ka = 10^{-pKa} = 10^{-4.76} = 1.74 \cdot 10^{-5}$

Now, by solving the equation of the solubility product for Herbigon, we can find [CH₃COO⁻]:

CH₃COOX ⇄ CH₃COO⁻ + X⁺

5.00x10⁻³ M

$K_{sp} = [CH_{3}COO^{-}][X^{+}]$

$[CH_{3}COO^{-}] = \frac{K_{sp}}{[X^{+}]} = \frac{9.40 \cdot 10^{-6}}{5.00 \cdot 10^{-3}} = 1.88 \cdot 10^{-3} M$

By entering the values of [CH₃COO⁻] and Ka, into equation (2) we can calculate [H₃O⁺]:

$[H_{3}O^{+}] = \frac{1.74 \cdot 10^{-5}*[1.00]}{[1.88 \cdot 10^{-3}]} = 9.26 \cdot 10^{-3} M$

Hence, the pH is:

$pH = -log [H_{3}O^{+}] = -log [9.26 \cdot 10^{-3}] = 2.03$

Therefore, the pH must be 2.03 to yield a solution in which the concentration of X⁺ is 5.00x10⁻³M.

I hope it helps you!

6 0

4 years ago

A gas is initially at a pressure of 4.7 atm and a volume of 7.5 L. When the volume is increased to 10.5 L, what is the new press

Roman55 [17]

Answer:

P2=3.36 atm

Explanation:

P1×V1=P2×V2

P1×V1÷V2=P2×V2÷V2

P2=4.7×7.5÷10.5

P2=3.36 atm

5 0

3 years ago

p32p32 is a radioactive isotope with a half-life of 14.3 days. if you currently have 63.163.1 g of p32p32 , how much p32p32 was

AlekseyPX

Answer:

92.93 g

Explanation:

Number of half lives that have elapsed in eight days =8/14.3 = 0.559

Fraction of the radioactive nuclide that remains after 0.559 half lives is given by

N/No=(1/2)^0.559

Where N= mass of radioactive nuclides remaining after a time t

No= mass of radioactive nuclides originally present

N/No=(1/2)^0.559= 0.679

Mass of nuclides present eight days before= 63.1g/0.679

Mass of nuclides present eight days before=92.93 g

6 0

4 years ago

Which combination of reagents used in the indicated order with benzene will give m-nitropropylbenzene? a. 1) CH3CH2CH2Cl/AlCl3,

VladimirAG [237]

Answer:

1) HNO3/H2SO4, 2) CH3CH2CH2Cl/AlCl3

Explanation:

Benzene is a stable aromatic compound hence it undergoes substitution rather than addition reaction.

When benzene undergoes substitution reaction, the substituent introduced into the ring determines the position of the incoming electrophile.

If I want to synthesize m-nitropropylbenzene, I will first carry out the nitration of benzene using HNO3/H2SO4 since the -nitro group is a meta director. This is now followed by Friedel Craft's alkykation using CH3CH2CH2Cl/AlCl3.

6 0

3 years ago

How much energy is needed to raise the temperature of 125g of water from 25.0oC to 35.0oC? The specific heat of water is 4.184

Anvisha [2.4K]

Hello!

To find the amount of energy need to raise the temperature of 125 grams of water from 25.0° C to 35.0° C, we will need to use the formula: q = mcΔt.

In this formula, q is the heat absorbed, m is the mass, c is the specific heat, and Δt is the change in temperature, which is found by final temperature minus the initial temperature.

Firstly, we can find the change in temperature. We are given the initial temperature, which is 25.0° C and the final temperature, which is 35.0° C. It is found by subtract the final temperature from the initial temperature.

35.0° C - 25.0° C = 10.0° C

We are also given the specific heat and the grams of water. With that, we can substitute the given values into the equation and multiply.

q = 125 g × 4.184 J/g °C × 10.0° C

q = 523 J/°C × 10.0° C

q = 5230 J

Therefore, it will take 5230 joules (J) to raise the temperature of the water.

6 0

4 years ago