Hãy so sánh và sắp xếp theo chiều tăng dần tính kim loại của các nguyên tố sau:<br> a) Al, Na,Mg, Si

It takes 42.25 ml of 0.0500 M Na2S2O3 solution to completely react with the iodine present in a 150.0 ml iodine solution. How ma

svlad2 [7]

Answer:

There were 0.268 grams I2 present

Explanation:

Step 1: Data given

Volume of Na2SO3 = 42.25 mL = 0.04225 L

Molarity of Na2SO3 = 0.0500 M

Volume of iodine = 150.0 mL

Step 2: The balanced equation

I2 + 2 Na2SO3 → Na2S2O6 + 2 NaI

Step 3: Calculate moles of Na2SO3

Moles Na2SO3 = molarity * volume

Moles Na2SO3 = 0.0500 M * 0.04225 L

Moles Na2SO3 = 0.0021125 moles

Step 4: Calculate moles I2

For 1 mol I2 we need 2 moles Na2SO3

For 0.0021125 moles Na2SO3 we have 0.00105625

Step 5: Calculate mass of I2

Mass I2 = moles * molar mass

Mass I2 = 0.00105625 * 253.8 g/mol

Mass I2 = 0.268 grams

There were 0.268 grams I2 present

3 0

4 years ago

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8. The reason water is polar is because A. in polar molecules atoms share electrons evenly. B. the electrons spend more time cir

pentagon [3]

Answer: option B happens to be correct since we can somewhere say that the electron density is more near oxygen atom which leads to polarization of bond and development of bond.

Explanation:

The reason why the water molecule is polar is due to the electronegativity difference between the Oxygen and hydrogen atoms.

Oxygen is more electronegative than hydrogen and hence the covalent bond formed between oxygen and hydrogen would be polarized . Since the oxygen is more electronegative than hydrogen so more electron density would remain around oxygen. Due to the bond polarity partial positive and negative charges would develop on the atoms.

Hydrogen would develop a partial positive charge since it is losing its electron density to more electronegative oxygen atom.

Oxygen would develop a partial negative charge as it is gaining electron density from hydrogen due to its more electronegativity.

The development of partial charges on account of polarity differences in polar molecules are not at all complete electron transfer.The bonds are still covalent in nature and the electrons are shared among atoms but just because one of the atoms is more electronegative so it is having more amount of electron density .

Out of the given options option B happens to be correct since we can somewhere say that the electron density is more near oxygen atom which leads to polarization of bond and development of bond.

8 0

3 years ago

How many moles of chloride ions are in 0.2550 g of aluminum chloride using AlCl3 's molar mass of 133.34 g / mol:?

Xelga [282]

I got 0.001912 using dimensional analysis. See the picture for work.

7 0

3 years ago

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How do I calculate the mass in grams of 8.0 mol lead oxide (PbO)?

omeli [17]

Answer:

Mass = 1785.6 g

Explanation:

Given data:

Moles of lead oxide = 8 mol

Mass in grams = ?

Solution:

Formula:

Number of moles = mass/ molar mass

Mass = number of moles × molar mass

Molar mass of PbO = 223.2 g/mol

Now we will put the values.

Mass = 8 mol × 223.2 g/mol

Mass = 1785.6 g

Thus 8 moles of lead oxide have 1785.6 grams.

5 0

3 years ago

Occasionally, deposition causes the main channel of a stream to divide into several smaller channels called _____.

timurjin [86]

ANSWER: D) distributaries

EXPLANATION: When a deposition causes the main channel of a stream to divide into several smaller channel it is called a distributary. They are a common feature of river deltas and is also known as river bifurcation. A distributary generally occurs near a lake or ocean and can also occur near a confluence of large stream. This is popularly also known as arm or channel.

8 0

3 years ago

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Hãy so sánh và sắp xếp theo chiều tăng dần tính kim loại của các nguyên tố sau: a) Al, Na,Mg, Si