USA test prep wave 1 performance task

Answer:

[tex]0.769\ \text{M}[/tex]

Explanation:

Mass of stock solution = 20 g

Molar mass of NaOH = 40 g/mol

Volume of stock solution = 0.150 mL

[tex]M_2[/tex] = Concentration of NaOH for the final solution

[tex]V_1[/tex] = Amount of stock solution taken = 15 mL

[tex]V_2[/tex] = Total volume of solution = 65 mL

Molarity is given by

[tex]M_1=\dfrac{\text{Mass}}{\text{Molar mass}\times \text{Volume}}\\\Rightarrow M_1=\dfrac{20}{40\times 0.15}\\\Rightarrow M_1=\dfrac{10}{3}[/tex]

We have the relation

[tex]M_1V_1=M_2V_2\\\Rightarrow M_2=\dfrac{M_1V_1}{V_2}\\\Rightarrow M_2=\dfrac{\dfrac{10}{3}\times 15}{65}\\\Rightarrow M_2=0.769\ \text{M}[/tex]

The concentration of NaOH for the final solution is [tex]0.769\ \text{M}[/tex].

Answer:

neutralization reaction is when an acid and a base react to form water and salt and involves the combination of hydrogen ions and hydroxyl ions to generate water. The neutralization of a strong acid and strong base has a pH equal to 7.

Answer:

Explanation:1. It is known that humans are in fact eating these tiny plastic particles, but fish aren't the only source. Bottled water, beer, honey, sea salt and tea bags have all been exposed as microplastic carriers, just to name a few.

2.The chemicals used in the production of plastic are toxic and detrimental to the human body. Chemicals in plastic-like lead, cadmium and mercury directly can come in contact with the humans. These toxins can cause cancers, congenital disabilities, immune system problems and childhood development issues.

3.Microplastics entering the human body via direct exposures through ingestion or inhalation can lead to an array of health impacts, including inflammation, genotoxicity, oxidative stress, apoptosis, and necrosis, which are linked to an array of negative health outcomes including cancer, cardiovascular diseases,

4.Human penises are shrinking because of pollution, warns scientist. ... Dr Shanna Swan writes that humanity is facing an "existential crisis" in fertility rates as a result of phthalates, a chemical used when manufacturing plastics that impacts the hormone-producing endocrine system

Answer:

7. Option D

Explanation:

Solubility increases with the increase in temperature of the solution. It is so because the increase in temperature leads to increase in kinetic energy which then breaks the solute particles held together by intermolecular attractions.

Hence, option D is correct

Answer:

HCO₂

Explanation:

From the information given:

The mass of the elements are:

Carbon C = 26.7 g;     Hydrogen H = 2.24 g     Oxygen O = 71.1 g

To determine the empirical formula;

First thing is to find the numbers of moles of each atom.

For Carbon:

[tex]=26.7 \ g\times \dfrac{1 \ mol }{12.01 \ g} \\ \\ =2.22 \ mol \ of \ Carbon[/tex]

For Hydrogen:

[tex]=2.24 \ g\times \dfrac{1 \ mol }{1.008 \ g} \\ \\ =2.22 \ mol \ of \ Hydrogen[/tex]

For Oxygen:

[tex]=71.1 \ g\times \dfrac{1 \ mol }{1.008 \ g} \\ \\ =4.44 \ mol \ of \ oxygen[/tex]

Now; we use the smallest no of moles to divide the respective moles from above.

For carbon:

[tex]\dfrac{2.22 \ mol \ of \ carbon}{2.22} =1 \ mol \ of \ carbon[/tex]

For Hydrogen:

[tex]\dfrac{2.22 \ mol \ of \ carbon}{2.22} =1 \ mol \ of \ hydrogen[/tex]

For Oxygen:

[tex]\dfrac{4.44 \ mol \ of \ Oxygen}{2.22} =2 \ mol \ of \ oxygen[/tex]

Thus, the empirical formula is HCO₂

Producers are the foundation of every food web in every ecosystem—they occupy what is called the first tropic level of the food web. The second trophic level consists of primary consumers—the herbivores, or animals that eat plants. At the top level are secondary consumers—the carnivores and omnivores who eat the primary consumers. Ultimately, decomposers break down dead organisms, returning vital nutrients to the soil, and restarting the cycle. Another name for producers is autotrophs, which means “self-nourishers.” There are two kinds of autotrophs. The most common are photoautotrophs—producers that carry out photosynthesis. Trees, grasses, and shrubs are the most important terrestrial photoautotrophs.  In most aquatic ecosystems, including lakes and oceans, algae are the most important photoautotrophs.

Answer:

Fires --> These consume fuel and convert chemical energy stored in that fuel into thermal light and sound energy.

Decay -->The breakdown of dead plants and animals releases thermal energy.

Earth --> Thermal energy comes from deep inside and it is called geothermal energy.

Answer:

B

Explanation:

Answer:

If you mix equal amounts of a strong acid and a strong base, the two chemicals essentially cancel each other out and produce a salt and water. Mixing equal amounts of a strong acid with a strong base also produces a neutral pH (pH = 7) solution.

Answer:

There are 2.85 x 10^22 atoms of carbon in a diamond with a mass of 0.568 g.

Hope this helps! :)

Answer:

To keep from falling apart

Explanation:

Answer:

2.44×10²³ molecules

Explanation:

From the question given above, the following data were obtained:

Mass of H₂O = 7.30 g

Number of molecules of H₂O =?

From Avogadro's hypothesis:

1 mole of H₂O = 6.02×10²³ molecules

1 mole of H₂O = (2×1) + 16

= 2 + 16

= 18 g

Thus,

18 g of H₂O = 6.02×10²³ molecules

Finally, we shall determine the number of molecules present in 7.3 g of H₂O. This can be obtained as follow:

From Avogadro's hypothesis:

18 g of H₂O = 6.02×10²³ molecules

Therefore,

7.3 g of H₂O = 7.3 × 6.02×10²³ / 18

7.3 g of H₂O = 2.44×10²³ molecules

Thus, 7.3 g of H₂O contains 2.44×10²³ molecules

Answer:

Well, there is no photo...

Explanation:

Answer:

[tex]V_2=1228.9L[/tex]

Explanation:

Hello there!

In this case, given the pressure, temperature and volume of the gas, we notice that we need the combined ideal gas as shown below:

[tex]\frac{P_2V_2}{T_2} =\frac{P_1V_1}{T_1}[/tex]

Thus, solving for the final volume, V2,  we would obtain:

[tex]V_2=\frac{P_1V_1T_2}{T_1P_2}[/tex]

Now, we plug in the data and make sure the temperature must be in Kelvins to obtain:

[tex]V_2=\frac{200atm*6.0L*(25+273)K}{(18+273.15)K(1.0atm)}\\\\V_2=1228.9L[/tex]

Best regards!

Answer:

36 atoms

Explanation:

The reactants are in the left side of the equation. First we determine how many atoms are there in the C₆H₁₂O₆ molecule:

There are two atoms in a O₂ molecule, and there are 6 O₂ molecules in the equation:

The total number of atoms in the reactants is

Answer:

C. 1000

l think this is correct answer

l hope it's helpful for you

Answer: 1. Highest osmotic pressure : 1 M [tex]MgCl_2[/tex]

2. Lowest osmotic pressure:  1 M [tex]C_{12}H_{22}O_{11}[/tex]

Explanation:

[tex]\pi=i\times C\times R\times T[/tex]

[tex]\pi[/tex]= osmotic pressure

i = Van'T Hoff factor  

C = concentration  

T = Temperature  

1. For 1M [tex]MgCl_2[/tex]  

, i= 3 as it is a electrolyte and dissociate to give 3 ions.

[tex]MgCl_2\rightarrow Mg^{2+}+2Cl^{-}[/tex]  

2. For 1 M [tex]KCl[/tex]

, i= 2 as it is a electrolyte and dissociate to give 2 ions.

[tex]KCl\rightarrow K^{+}+Cl^{-}[/tex]

3. For  1M [tex]C_{12}H_{22}O_{11}[/tex]

, i= 1 as it is a non electrolyte and do not dissociate.  

Thus as vant hoff factor is highest for [tex]MgCl_2[/tex] thus osmotic pressure is highest for 1 M [tex]MgCl_2[/tex]

And as vant hoff factor is lowest for [tex]C_{12}H_{22}O_{11}[/tex] thus osmotic pressure is lowest for  1 M [tex]C_{12}H_{22}O_{11}[/tex]

Answer:

The limiting reactant is: H₂O

265.3 g of K₂Sn(OH)₆ are formed in the reaction.

Explanation:

The reaction is:

Sn(s) + 2KOH (aq) + 4H₂O(l)  → K₂Sn(OH)₆ (s) + 2H₂ (g)

The first step to solve is to determine the moles of each reactant:

We controlled that reaction is ballanced.

122 g . 1mol / 118.71g = 1.03 moles of Sn

134g . 1mol /56.1g = 2.39 moles of KOH

63.9 g .1mol /18g = 3.55 mol of water

Stoichiometry is 1:2:4.

Sn is the lowest reactant and water, the highest, but I can see, that water is the limiting.

1 mol of Sn needs 4 moles of H₂O to react

Then, 1.03 moles of Sn may react to (1.03 . 4)/1 = 4.12 moles.

We only have 3.55 moles. It's ok.

2 moles of KOH need 4 moles of H₂O to react

Then, 2.39 moles of KOH may react to (2.39 . 4) /2 = 4.78 moles.

We only have 3.55, there's no enough water.

So 4 moles of water can produce 1 mol of potassium hydroxystannate

Then, 3.55 moles of H₂O may produce (3.55 . 1)/4 = 0.8875 moles.

We convert moles to mass: 0.08875 mol . 298.91g /1mol =265.3g

Answer:

Attached picture.

Explanation:

(1) Ksp equals the product of [Co 2+][CO3 2-]. CoCO3 is excluded from the equilibrium expression because it is a pure solid. The mole ratio of Co 2+ and CO3 2- is 1:1 so their molar solubilities are the same.

(2) There is an initial concentration of 0.10 M Co 2+ so write that in the "I" row for Co 2+ on the ICE table. When you find the zeros of the quadratic when solving for "s", take the positive value rather than the negative value because concentration cannot be negative.

(3) Extra products will cause the equilibrium to consume products and form reactants. So the reverse reaction will occur faster than the forward reaction. More products mean an increased Q value compared to K, since the numerator of [tex]K = \frac{[products]}{[reactants]}[/tex] increases.

Answer:

14

Explanation:

Step 1: Calculate the moles corresponding to 25 g of Ba(OH)₂

The molar mass of Ba(OH)₂ is 171.34 g/mol.

25 g × 1 mol/171.34 g = 0.15 mol

Step 2: Calculate the molar concentration of Ba(OH)₂

Molarity is equal to the moles of solute divided by the liters of solution.

[Ba(OH)₂] = 0.15 mol/0.250 L = 0.60 M

Step 3: Calculate the molar concentration of OH⁻

Ba(OH)₂ is a strong base according to the following equation.

Ba(OH)₂ ⇒ Ba²⁺ + 2 OH⁻

The molar ratio of Ba(OH)₂ to OH⁻ is 1:2. The molar concentration of OH⁻ is 2/1 × 0.60 M = 1.2 M.

Step 4: Calculate the concentration of H⁺

We will use the ionic product of water expression.

Kw = 1.0 × 10⁻¹⁴ = [H⁺] × [OH⁻]

[H⁺] = 1.0 × 10⁻¹⁴/[OH⁻] = 1.0 × 10⁻¹⁴/1.2 = 8.3 × 10⁻¹⁵ M

Step 5: Calculate the pH of the solution

We will use the definition of pH.

pH = -log [H⁺] = -log 8.3 × 10⁻¹⁵ = 14

Answer:

A) atomic size

Explanation:

Answer: C.

Explanation:

two H nuclei fused into one He nucleus

Answer: A!

Explanation: just did it

Answer:

A.

Explanation:

In an endothermic reaction heat is applied.

In an endothermic process, heat is transferred from the surroundings to the system.

What are endothermic and exothermic processes?

An exothermic process is one that gives off heat. This heat is transferred to the surroundings. An endothermic process is one in which heat has to be supplied to the system from the surroundings.

The endothermic process is a term that describes a reaction where the system absorbs the energy from its surrounding in the form of heat. A few examples of the endothermic process are photosynthesis, evaporating liquids, melting ice, etc.

The exothermic reaction is the opposite of an endothermic reaction. It releases energy by light or heat to its surrounding. A few examples are neutralization, burning of a substance, reactions of fuels, etc.

Hence, option A is the correct answer.

Learn more about endothermic and exothermic processes here:

https://brainly.com/question/4345448

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Answer:

9 moles

Explanation:

The balanced chemical equation provided in this question is as follows:

2CH₄ + S₈ → 2CS₂ + 4H₂S

In accordance to the above balanced equation, 1 mole of sulphur (S8) produces 4 moles of hydrogen sulfide (H2S).

Therefore, if 2.25mol of S8 is used, 2.25 × 4 = 9 mol

9 moles of H2S is produced.

Answer:

Calcium flouride?

Explanation:

Quite self explanatory