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3 years ago

What chemical reaction does this equation represent?

1 answer:

4 0

Answer is: D: Two molecules of potassium chloride react with one molecule of lead nitrate to form two molecules of potassium nitrate and one molecule of lead chloride.

Balanced chemical reaction: 2KCl + Pb(NO₃)₂ → 2KNO₃ + PbCl₂.

According to principle of mass conservation, number of atoms must be equal on both side of balanced chemical reaction.

KCl - potassium chloride.

Pb(NO₃)₂ - lead nitrate.

KNO₃ - potassium nitrate.

PbCl₂ - lead chloride.

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How did you use QPOE?

Jlenok [28]

QPOE Files

The x-ray data are stored in QPOE files (Quick Position-Ordered Events, *.qp) rather than image arrays. These are lists of photons identified by several quantities, including the position on the detector, pulse height, and arrival time. Note that, unlike IRAF images, QPOE files have no associated header file, and are always stored in the current directory, unless explicitly specified otherwise. Non-PROS IRAF tasks can also access QPOE data files in place of image arrays.

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3 years ago

Give one chemical property of soda ash.

Elenna [48]

Soda ash is sodium carbonate, Na2CO3. One chemical property of this compound is its basicity, which is measured by the pKb. The pKb for sodium carbonate is 3.67. It is the result of the dissociation of Na2CO3 in water: Na2CO3 + H2O = Na HCO3 + Na (+) + OH(-). This pKb means that it is a highly basic compound. pKb = log { 1 / [OH-] }, so pKb is a measure of the concentrations of OH- ions, which is the basiciity of the compound.

4 0

3 years ago

How many grams of zinc would be required to produce 9.65g of zinc hydroxide

Effectus [21]

The question is incomplete, here is the complete question:

How many grams of zinc would be required to produce 9.65g of zinc hydroxide

Zn+2MnO₂+H₂O→Zn(OH)₂+Mn₂O₃

Answer: The mass of zinc required is 6.35 grams

Explanation:

To calculate the number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$ .....(1)

Given mass of zinc hydroxide = 9.65 g

Molar mass of zinc hydroxide = 99.4 g/mol

Putting values in equation 1, we get:

$\text{Moles of zinc hydroxide}=\frac{9.65g}{99.4g/mol}=0.0971mol$

The given chemical equation follows:

$Zn+2MnO_2+H_2O\rightarrow Zn(OH)_2+Mn_2O_3$

By Stoichiometry of the reaction:

1 mole of zinc hydroxide is produced from 1 mole of zinc

So, 0.0971 moles of zinc hydroxide will be produced from = $\frac{1}{1}\times 0.0971=0.0971mol$ of zinc

Now, calculating the mass of zinc from equation 1, we get:

Molar mass of zinc = 65.4 g/mol

Moles of zinc = 0.0971 moles

Putting values in equation 1, we get:

$0.0971mol=\frac{\text{Mass of zinc}}{65.4g/mol}\\\\\text{Mass of zinc}=(0.0971mol\times 65.4g/mol)=6.35g$

Hence, the mass of zinc required is 6.35 grams

6 0

3 years ago

Which piece of glassware shown below is used to hold and dispense a solution of known concentration during a titration?

Musya8 [376]

Answer:

Answer C

Explanation:

Got it off of q**zlet ;)

4 0

3 years ago

How many significant figures are there in the following numbers: 10.78, 6.78, 0.78? If these were pH values, to how many signifi

Ksivusya [100]

Answer:

10.78 → 4 significant figures, pH = 10.78 → [H⁺] = 1.66ₓ10⁻¹¹ M

6.78 → 3 significant figures, pH = 6.78 → [H⁺] = 1.66ₓ10⁻⁷ M

0.78 → 2 significant figures, pH = 0.78 → [H⁺] = 0.166 M

pH always can be expressed by at least 4 significant figures. The [H⁺], can be expressed by, at least 3 significant figures

Explanation:

Significant figures are the numbers of a measurement that have certainty plus a doubtful number (it is associated with the uncertainty in the measurement). For example, if we measure a paper with a ruler and the ruler measures up to centimeters we can say that the paper is 7.5 cm long, with which we know that the paper is 7 cm + 0.5 cm which we associate with uncertainty. In this case we talk about two significant figures. If the sheet measured 7.57 cm we would already be talking about a more precise measurement and in this case with 3 significant figures.

10.78 → 4 significant figures

6.78 → 3 significant figures

0.78 → 2 significant figures

To determine [H⁺], we apply 10^-pH

10⁻¹⁰°⁷⁸ = 1.66ₓ10⁻¹¹ M

10⁻⁶°⁷⁸ = 1.66ₓ10⁻⁷ M

10⁻⁰°⁷⁸ = 0.166 M

3 0

3 years ago