chemistry question, 20 points, will mark as brainliest if correct:

Answer:

b, and d

Explanation:

if the student did not aim correctly, and for d if the light waves travelled differently

Answer:

B + C ARE INCORRECT FROM THE ABOVE GIVEN CONVERSIONS.

Answer:

C

Explanation:

Answer: D. Friction between two rock surfaces grinding away minerals.

Explanation: chemical weathering involves erosion from rocks/materials

Answer:

Answer A  

Explanation:

2 H2  +  O2  = 2 H2O  

  knowing the mole weights of these elements shows O2 is the limiting reactant in this situation.

4 g oxygen is  4 /31.998  = .125 mole O2

  We should get two times these moles of water = .250 moles

         weight = .250 (1.008 * 2  + 15.999) =  4.50 gm H20   (theoretical)

   ....but we only got 4 gm

4/4.50  =  88.8%  

If a wildfire occurred in the Everglades, the insect which most likely to survive predator is gray-colored speckled moth.

Predators are those animals which for their survival will hunt or kill another animals for the fulfilment of their food need.

If wildfire occured in the everglades region then the insect would be the most likely to survive predators in an ash and soot covered habitat is gray-colored speckled moth which is also known as darwin moth as it takes part in evolution of natural process.

Hnece the required animal is gray-colored speckled moth.

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nebula

All stars start in a large cloud of dust and gas called a nebula. Gravity can pull some of the gas and dust in a nebula together, forming a proto-star. A star is born when the gas and dust from a nebula become so hot and dense that hydrogen atoms are smashed together to form helium.

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The total number of Ca2+ ions and F- ions that are present in the cubic unit cell will be 4 and 8 respectively.

From the complete information, the number of Ca2+ at corners will be (8 × 1/8 = 1) and those a the center will be (6 × 1/2 = 3). Therefore, the total number of Ca2+ will be:

= 1 + 3 = 4

The total number of F- ions will be:

= 4 × 2 = 8

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Without conducting an experiment, one can determine if a species in a solution is acidic or basic by using a litmus paper.

Acidic species would turn a blue litmus paper to red but have no effects on red litmus paper.

Basic species would turn a red litmus paper to blues but have no effects on blue litmus paper.

Thus, in order to determine if a species in a solution is acidic or basic without conducting any experiment, dipping a litmus paper into the solution would give an indication.

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Apply Charles law

Answer:

All of the above :D

Explanation:

When rain falls, if it doesn't get absorbed by the dirt, it will go into streams, rivers, and ponds. That is actually how flooding is caused!!! :D

Have an amazing day!!

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Answer:

C

Explanation:

It has the lowest Ksp, so it will have the lowest Molar Solubility

Answer:

Cl2

Explanation:

Chlorine is a diatomic element  so it is   Cl 2

 the others are MOLECULES  (made up of atoms of ELEMENTS)

Answer:The larva might form a cocoon or a chrysalis.

Explanation:

Answer:

This means that one mole of water molecules has a mass of 18.015g.

42.3g * 1 mole H2O/18.015g

= 2.3480 moles H2O

We are using the avogadros number to find the number of molecules of water

2.3480 H2O * 6.022*10^ 23moles/ 1mole of H2O

That's 2.3480 multiplied by 6.022*10^23 divided by 1 mole of H2O

Number of molecules = 1.4140 *10^24 molecules

Answer: can hydrogen produce as much energy as burning fossil fuels?

Explanation:

1. Acids have highest concentration of hydronium ions.

2. Bases have highest concentration of Hydroxide ions

3. a. less than 7 b. more than 7

4. Acids (Presence of hydronium ions)

You need Conclusions too?

Step 1: Write the balanced "molecular equation:

[tex]2HI(aq) + CrCO₃ (s) → CrI₂ (s) + H₂O(l) + CO₂(g)[/tex]

Step 2: Carbon dioxide and water are written in molecular form. Consult the solubility and net ionic equation rules on the information page to determine which of the other substances will dissociate:

[tex]2HI(aq) + CrCo₃ (s) → Crl₂ (s) +H₂O(l)+CO₂(g)[/tex]

yes no yes

Step 3: Dissociate all soluble salts, strong acids, and strong bases (except calcium hydroxide), Leave together all "not soluble" salts and weak acids or bases:

[tex] {2H₂O}^{ + } (aq) + {2I}^{ - } (aq) + CrCO₃ (s)→ {Cr}^{2 + } (aq) + {2I}^{ - }(aq) + 3H₂O(l) + CO₂(g)[/tex]

Step 4: Cross out "spectator lons that appear on both sides of the reaction (these lons do not participate in the chemistry) and rewrite the "net" reaction using the smallest possible coefficients:

[tex] {2H₂O}^{ + } (aq) + CrCO₃ (s) →3H₂O + CO₂ + {Cr}^{2 + } [/tex]

Dancing is a physical activity which strengthens the abdominal and calf muscles as well as improves flexibility.

A physical activity is any activity which involves movement of the body in order to strengthen the muscles and to be physically fit.

Dancing is a physical activity which involves intricate and repeated movements of the body.

Dancing is beneficial because;

Some muscles involved in dancing include;

Some risks in dancing include muscle injuries, dislocations and possibly fractures due to falls.

Therefore, a dancing routine strengthens the abdominal and calf muscles as well as improves flexibility.

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Answer: 4.4 x 10^-7

Explanation:

The dissociation equation for this reaction is:

MgCO3 (s) → Mg+2 (aq) + CO3-2 (aq)

[tex]\text { So, } k_{s p}=(x+0.08) x[/tex] (Here 0.08 >>> x )

[tex]\begin{aligned}\Rightarrow 3.5 \times 10^{-8} &=0.08 \times x \\\Rightarrow x &=\frac{3.5}{0.08} \times 10^{-8} \\&=4.37 \times 10^{-7} \\\Rightarrow x & \approx 4.4 \times 10^{-7} \mathrm{~M}\end{aligned}[/tex]

So the solubility MgCO₃ in a solution that containing 0.080 M Mg²⁺ is 4.4 x 10^-7

Here are the balanced equations

Done!

Answer:

About 4.63.

Explanation:

The reaction between ethanoic acid (CH₃COOH) and sodium hydroxide (NaOH) can be described by the following net ionic equation:

[tex]\displaystyle \text{CH$_3$COOH}_\text{(aq)} + \text{OH}^-_\text{(aq)}\longrightarrow \text{CH$_3$COO}^-_\text{(aq)} + \text{H$_2$O}_\text{($\ell$)}[/tex]

40.0 mL of 0.040 M NaOH contains:
[tex]\displaystyle 40.0\text{ mL} \cdot \frac{0.040\text{ mol NaOH}}{1000\text{ mL}} = 0.0016\text{ mol NaOH}[/tex]

Because NaOH is a strong base, it dissociates completely. Hence, the amount of OH⁻ present is 0.0016 mol. Na⁺ acts as a spectator ion.

50.0 mL of 0.075 M CH₃COOH contains:
[tex]\displaystyle 50.0\text{ mL} \cdot \frac{0.075\text{ mol CH$_3$COOH}}{1000\text{ mL}} = 0.0038\text{ mol CH$_3$COOH}[/tex]

OH⁻ is the limiting reagent of the reaction. Therefore, as the reaction proceeds to completion:

Note that all species present are in a one-to-one ratio.

To find pH, we can use the Henderson-Hasselbalch equation:

[tex]\displaystyle \text{pH} = \text{p}K_a + \log\frac{[\text{Base}]}{[\text{Acid}]}[/tex]

The total volume of the solution is 40.0 mL + 50.0 mL = 90.0 mL.

Hence, find [CH₃COOH]:

[tex]\displaystyle \left[\text{CH$_3$COOH}\right] = \frac{0.0022\text{ mol}}{90.0\text{ mL}} \cdot \frac{1000\text{ mL}}{1\text{ L}} = 0.024\text{ L}[/tex]

Find [CH₃COO⁻]:
[tex]\displaystyle \left[\text{CH$_3$COO}^-\right] = \frac{0.0016\text{ mol}}{90.0\text{ mL}}\cdot \frac{1000\text{ mL}}{1\text{ L}} = 0.018\text{ M}[/tex]

Therefore, the pH of the resulting solution is:
[tex]\displaystyle \begin{aligned}\text{pH} & = \text{p}K_a + \log\frac{[\text{Base}]}{[\text{Acid}]} \\ \\ & = (4.75) + \log \frac{(0.018)}{(0.024)} \\ \\ & = 4.75 + (-0.12) \\ \\ & = 4.63\end{aligned}[/tex]

In conclusion, the pH of the resulting solution is about 4.63.

Answer:

The answer is aluminum foil.

Answer:

For yogurt production, probiotic bacteria and the Streptococcus thermophilus strain work together to produce a stable balance of bacteria in the culture.

Answer:

The answer is c.........

Answer:

3.8 M

Explanation:

Mole weight of LiCl = 6.94 + 35.45 = 42.39    ( from periodic table)

175 g of this is then   175 / 42.39  = 4.13 moles

4.13 moles / (1085/1000) = 3.8 M

The major product of the reaction between  acetic anhydride and CH3CH2CH2OH is CH3COOCH2CH2CH3. While, the major product of the reaction between acetic anhydride and NH3 is CH3CONH2.

Acetic anhydride is the compound (CH3COO)2. It is a precursor for the synthesis of many organic compounds.

Now let us consider the use of acetic anhydride in synthesis. The major product of the reaction between  acetic anhydride and CH3CH2CH2OH is CH3COOCH2CH2CH3. While, the major product of the reaction between acetic anhydride and NH3 is CH3CONH2.

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Answer:

Option B: Oxygen.

Explanation:

Hope this helped.

Answer:

.018 M

Explanation:

Mole weight of NaCl (from periodic chart) = 58.44 g /mole

4 g / 58.44 gm/mole = .06845 mole

.06845 mole / (3.8 liter ) = .018 M

The molarity of a new solution that has a volume of 25.0 mL of a 2.00 M HCl solution and diluted to 2.00 L is 0.025M.

The molarity of a solution can be calculated using the following formula:

C1V1 = C2V2

Where;

2 × 25 = 2000 × C2

50 = 2000C2

C2 = 50 ÷ 2000

C2 = 0.025M

Therefore, the molarity of a new solution that has a volume of 25.0 mL of a 2.00 M HCl solution and diluted to 2.00 L is 0.025M.

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