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3 years ago

a cup of hot water cannot melt a large block of ice. However the same block melts when dropped into a lake. This is because?

1 answer:

5 0

This is because the salt in the lake lowers the freezing point. Salt makes a great ice melter, but salt cannot melt ice with just itself.

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What does pressure measure

omeli [17]

Answer:

Explanation:

Pressure it says it in the name its the force of colliding particles

6 0

4 years ago

CuSO4.5H2O(k) ısı CuSO4(k) + 5 H2O(g) eşitliğine göre bakır sülfatın kristal suyu miktarı ve kaba formülü hesaplanacaktır.

baherus [9]

Answer:

159.609 g/mol

Explanation:

According to the CuSO4.5H2O (k) heat CuSO4 (k) + 5 H2O (g) equation, the crystal water amount of copper sulfate and its rough formula will be calculated.

Weight of copper sulfate containing crystal water = m1 = 249.62… g

Weight of copper sulfate without crystal water weighed = m2 = 159.62 g

Accordingly, calculate the x and y values in the molecular formula of copper sulfate (xCuSO4.yH2O).

3 0

3 years ago

List four metals that will mot replace hydrogen in an acid

sdas [7]

The four metals that will not replace hydrogen in an acid are Cu, Ag, Au, Hg.

Explanation:

As Copper Cu lies below the hydrogen, this is why it is less reactive and ca not replace Hydrogen from its compound.

Silver Ag also lies below the hydrogen and therefore it is less reactive to displace Hydrogen.

Gold Au becomes less reactive than Hydrogen due to its placement below Hydrogen acid.

Mercury Hg is less reactive than Hydrogen

7 0

3 years ago

Given the two reactions PbCl2(aq)⇌Pb2+(aq)+2Cl−(aq), K3 = 1.89×10−10, and AgCl(aq)⇌Ag+(aq)+Cl−(aq), K4 = 1.25×10−4, what is the

Sergio [31]

Answer:

$1.2\times 10^{-2}$

Explanation:

The given reactions are:

PbCl2(aq)⇌Pb2+(aq)+2Cl−(aq) $K_3 = 1.89\times 10^{-10}$

AgCl(aq)⇌Ag+(aq)+Cl−(aq) $K_4 = 1.25\times 10^{-4}$

Required reaction is:

PbCl2(aq)+2Ag+(aq)⇌2AgCl(aq)+Pb2+(aq)

$K_f = \frac{K_3}{K_4^2}\\=\frac{1.89\times 10^{-10}}{1.25\times 10^{-4}}^2\\=1.2\times 10^{-2}$

4 0

4 years ago

The electrolysis of water forms H2 and O2. 2H2O 2H2 + O2 What is the percent yield of O2 if 10.2 g of O2 is produced from the de

BigorU [14]

<u>Answer:</u> The percent yield of oxygen gas is 67.53 %.

<u>Explanation:</u>

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 water = 17.0 g

Molar mass of water = 18 g/mol

Putting values in equation 1, we get:

$\text{Moles of water}=\frac{17.0g}{18g/mol}=0.944mol$

For the given chemical equation:

$2H_2O\rightarrow 2H_2+O_2$

By Stoichiometry of the reaction:

2 moles of water produces 1 mole of oxygen gas

So, 0.944 moles of water will produce = $\frac{1}{2}\times 0.944=0.472moles$ of oxygen gas

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

Molar mass of oxygen gas = 32 g/mol

Moles of oxygen gas = 0.472 moles

Putting values in equation 1, we get:

$0.472mol=\frac{\text{Mass of oxygen gas}}{32g/mol}\\\\\text{Mass of oxygen gas}=(0.472mol\times 32g/mol)=15.104g$

To calculate the percentage yield of oxygen gas, we use the equation:

$\%\text{ yield}=\frac{\text{Experimental yield}}{\text{Theoretical yield}}\times 100$

Experimental yield of oxygen gas = 10.2 g

Theoretical yield of oxygen gas = 15.104 g

Putting values in above equation, we get:

$\%\text{ yield of oxygen gas}=\frac{10.2g}{15.104g}\times 100\\\\\% \text{yield of oxygen gas}=67.53\%$

Hence, the percent yield of oxygen gas is 67.53 %.

7 0

4 years ago

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