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3 years ago

When does a phyisical change occur?

1 answer:

ioda3 years ago

6 0

Physical changes occur when objects or substances undergo a change that does not change their chemical composition. This contrasts with the concept of chemical change in which the composition of a substance changes or one or more substances combine or break up to form new substances.

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Which of the following kinds of milk has the highest fat content? If you are right I will mark you Brainliest.

Deffense [45]

Answer:

Explanation:

Uh whipping cream is that like whip cream thats in a can that when u press it down cream comes out? if so then yeah because that has alot of sugar other than 1% milk

4 0

3 years ago

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A mixture of nitrogen and hydrogen gases, at a total pressure of 663 mm Hg, contains 3.46 grams of nitrogen and 0.156 grams of h

STALIN [3.7K]

Answer: The partial pressure of nitrogen gas is 405.76 mmHg and that of hydrogen gas is 257.24 mmHg

Explanation:

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

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$

For nitrogen gas:

Given mass of nitrogen gas = 3.46 g

Molar mass of nitrogen gas = 28 g/mol

Putting values in above equation, we get:

$\text{Moles of nitrogen gas}=\frac{3.46g}{28g/mol}=0.123mol$

For hydrogen gas:

Given mass of hydrogen gas = 0.156 g

Molar mass of hydrogen gas = 2 g/mol

Putting values in above equation, we get:

$\text{Moles of hydrogen gas}=\frac{0.156g}{2g/mol}=0.078mol$

Mole fraction of a gas is calculated by using the formula:

$\chi_{A}=\frac{n_{A}}{n_{A}+n_{B}}$ ......(1)

For nitrogen gas:

Putting values in equation 1, we get:

$\chi_{\text{nitrogen gas}}=\frac{0.123}{0.123+0.078}=0.612$

For hydrogen gas:

Putting values in equation 1, we get:

$\chi_{\text{hydrogen gas}}=\frac{0.078}{0.123+0.078}=0.388$

The partial pressure of a gas is given by Raoult's law, which is:

$p_A=p_T\times \chi_A$ ......(2)

where,

$p_A$ = partial pressure of substance A

$p_T$ = total pressure = 663 mmHg

$\chi_A$ = mole fraction of substance A

For nitrogen gas:

$p_{\text{Nitrogen gas}}=663mmHg\times 0.612\\\\p_{\text{Nitrogen gas}}=405.76mmHg$

For hydrogen gas:

$p_{\text{Hydrogen gas}}=663mmHg\times 0.388\\\\p_{\text{Hydrogen gas}}=257.24mmHg$

Hence, the partial pressure of nitrogen gas is 405.76 mmHg and that of hydrogen gas is 257.24 mmHg

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3 years ago

Which type of bond is formed from sharing electrons?

Harrizon [31]

Covelant molecules are formed d

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4 years ago

Ocean exploration is limited by

Alex777 [14]

It is limited by the depth divers and equipment can go.

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3 years ago

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whg doe sthe transfer of electrons from magnesium to oxygen cause the ions produced to attract eachother

almond37 [142]

Oxygen gains two electrons when it bonds to form a complete outer shell and magnesium loses two electrons when bonding to gain its full outer shell.

As electrons are negative, the oxygen (which gains electrons) will become negative and the magnesium (which loses electrons) will become positive.

The negative and positive ions will then attract to one another due to the magnetic pull of the positive and negative.

8 0

4 years ago