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2 years ago

How is energy in a washing machine being utilised and wasted?

Chemistry

2 answers:

7nadin3 [17]2 years ago

8 0

Answer:

It depends on whether the setting is hot or cold .-.

Explanation:

lana66690 [7]2 years ago

6 0

Wasted= sound
Utilised=movement

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Treatment of butanedioic (succinic) anhydride with ammonia at elevated temperature leads to a compound of molecular formula C4H5

artcher [175]

Answer:

The product is Methyl cyanoacetate

Explanation: see structure attached

5 0

2 years ago

Part 1: Name the type of chemical reaction that occurs when calcium hydroxide (Ca(OH)2) reacts with nitric acid (HNO3).

liberstina [14]

Answer:

For 1: Neutralization reaction

For 2: Zinc is more reactive than lead and less reactive than calcium.

Explanation:

For (1):

When a base reacts with an acid to form a salt and water molecule, it is known as a neutralization reaction. The general equation follows:

$HX+BOH\rightarrow BX+H_2O$

The chemical equation for the reaction of calcium hydroxide and nitric acid follows:

$Ca(OH)_2(aq)+2HNO_3(aq)\rightarrow Ca(NO_3)_2(aq)+2H_2O(l)$

For (2):

A single displacement reaction is defined as the reaction in which a more reactive metal displaces a less reactive metal from its salt solution. The general chemical equation follows:

$A+BX\rightarrow AX+B$

where,

Metal A is more reactive than metal B

The reactivity of metals is judged by the reactivity series where a metal lying above in the series is more reactive than the metal lying below it.

From the reactivity series below,

Zinc lies above in the series than lead thus is more reactive and will easily replace lead from its aqueous solution.

While zinc lies below in the series than calcium thus is less reactive and will not easily replace calcium from its aqueous solution.

$Zn(s)+Pb(NO_3)_2(aq)\rightarrow Zn(NO_3)_2(aq)+Pb(s)$

$Zn(s)+CaCl_2(aq)\rightarrow \text{No reaction}$

5 0

3 years ago

A solution has a [H3O+] of 1x 10-5 M. What is the [OH-] of the solution? (5 points)

White raven [17]

Answer:

1x10^–9 M

Explanation:

From the question given,

Concentration of hydronium ion, [H3O+] = 1x10^-5 M.

Concentration of Hydroxide ion, [OH-] =..?

The concentration of the hydroxide ion, [OH-] can be obtained as follow:

[H3O+] x [OH-] = 1x10^–14

1x10^-5 M x [OH-] = 1x10^–14

Divide both side by 1x10^-5

[OH-] = 1x10^–14 / 1x10^-5

[OH-] = 1x10^–9 M

8 0

3 years ago

Wild animals are not considered a natural resource.

Anvisha [2.4K]

Answer:

False

Explanation:

Wild animals are found in an ecosystem and they are considered to be a natural resource and a biotic factor in the environment. They are living things so they are a natural resource.

4 0

3 years ago

An unknown compound, X is thought to have a carboxyl group with a pKa of 2.0 and another ionizable group with a pKa between 5 an

Westkost [7]

Answer:

7.3

Explanation:

By Henderson Hasselbalch equation we can calculate the pH or the pOH of a solution by its pKa. Remember that $pH = -log[H^{+}]$ , and pKa = -logKa. Ka is the equilibrium constant of the acid.

Henderson Hasselbalch equation :

$pH = pKa - log \frac{[HA]}{[A^{-}]}$

Where [HA] is the concentration of the acid, and $[A^{-}]$ is the concentration of the anion which forms the acid.

So, acid X, has two ionic forms, the carboxyl group and the other one. First, we have 0.1 mol/L of the acid, in 100 mL, so the number of moles of X

n1 = (0.1 mol/L)x(0.1 L) = 0.01 mol

When it dissociates, it forms 0.005 mol of the carboxyl group and 0.005 mol of the other group. Assuming same stoichiometry.

Adding NaOH, with 0.1 mol/L and 75 mL, the number of moles of $OH^-$ will be

n2 = (0.1 mol/L)x(0.075 L) = 0.0075 mol

So, the 0.0075 mol of $OH^-$ reacts with 0.005 mol of carboxyl, remaining 0.0025 mol of $OH^-$ , which will react with the 0.005 mol of the other group. So, it will remain 0.0025 mol of the other group.

The final volume of the solution will be 175 mL, but both concentrations (the acid form and ionic form) have the same volume, so we can use the number of mol in the equation.

Note that, the number of moles of the acid form is still 0.01 mol because it doesn't react!

So,

$6.72 = pKa - log \frac{0.01}{0.0025}$

6.72 = pKa - log 4

pKa - log4 = 6.72

pKa = 6.72 + log4

pKa = 6.72 + 0.6

pKa = 7.3

8 0

3 years ago