What volume of a 3.95 M

Which description applies to all of an element

lukranit [14]

An atom is the smallest you can get to identify the element.

8 0

2 years ago

While you were "sweating" your chemistry test, water vapor evaporates from your body, absorbing 50,000 J of energy. (assume no

TiliK225 [7]

Answer:

$\boxed {\boxed {\sf B. \ 22 \ grams}}$

Explanation:

We need to use the formula for heat of vaporization.

$Q=H_{vap}*m$

Identify the variables.

The heat absorbed by the evaporating water is the <u>latent heat of vaporization. </u>For water, that is 2260 Joules per gram.

Q is the energy, in this problem, 50,000 Joules.

m is the mass, which is unknown.

$H_{vap}=2260 \ J/g\\Q=50,000 \ J \\$

Substitute the values into the formula.

$50,000 \ J=2260 \ J/g*m$

We want to find the mass. We must isolate the variable, m.

m is being multiplied by 2260 J/g. The inverse operation of multiplication is division. Divide both sides by 2260 J/g.

$\frac{50,000 \ J}{2260 \ J/g} =\frac{2260 \ J/g*m}{2260 \ J/g}$

$\frac{50,000 \ J}{2260 \ J/g} =m$

Divide. Note that the Joules (J) will cancel each other out.

$\frac{50,000 \ }{2260 \ g} =m$

$22.1238938 \ g =m$

Round to the nearest whole number. The 1 in the tenth place tells us to leave the number as is.

$22 \ g \approx m$

The mass is about 22 grams, so choice B is correct.

3 0

2 years ago

How many moles of Carbon are in 3.06 g of Carbon

natta225 [31]

Answer:

$\boxed {\boxed {\sf 0.255 \ mol \ C }}$

Explanation:

If we want to convert from grams to moles, the molar mass is used. This is the mass of 1 mole. They are found on the Periodic Table as the atomic masses, but the units are grams per mole (g/mol) instead of atomic mass units (amu).

Look up the molar mass of carbon.

Carbon (C): 12.011 g/mol

Set up a ratio using the molar mass.

$\frac {12.011 \ g \ C}{ 1 \ mol \ C}$

Since we are converting 3.06 grams to moles, we multiply by that value.

$3.06 \ g \ C*\frac {12.011 \ g \ C}{ 1 \ mol \ C}$

Flip the ratio. This way, the ratio is still equivalent, but the units of grams of carbon cancel.

$3.06 \ g \ C* \frac{1 \ mol \ C}{12.011 \ g\ C}$

$3.06 * \frac{1 \ mol \ C}{12.011 }$

$\frac {3.06}{12.011 } \ mol \ C$

$0.25476646 \ mol \ C$

The original measurement of grams (3.06) has 3 significant figures, so our answer must have the same. For the number we calculated, that is the thousandth place.

0.25476646

The 7 in the ten-thousandth place tells us to round the 4 up to a 5.

$0.255 \ mol \ C$

3.06 grams of carbon is approximately <u>0.255 moles of carbon.</u>

3 0

1 year ago

If the atmospheric pressure is 0.975 atm what is the pressure of the enclosed gas

Nuetrik [128]

Missing in your question:
Picture (1)
when its an open- tube manometer and the h = 52 cm.
when the pressure of the atmosphere is equal the pressure of the gas plus the pressure from the mercury column 52 Cm so, we can get the pressure of the gas from this formula:
P(atm) = P(gas) + height (Hg)
∴P(gas) = P(atm) - height (Hg)
= 0.975 - (520/760)
= 0.29 atm
Note: I have divided 520 mm Hg by 760 to convert it to atm
Picture (2)
The pressure of the gas is the pressure experts by the column of mercury and when we have the Height (Hg)= 67mm
So the pressure of the gas =P(atm) + Height (Hg)
= 0.975 + (67/ 760) = 1.06 atm
Picture (3)
As the tube is closed SO here the pressure of the gas is equal the height of the mercury column, and when we have the height (Hg) = 103 mm. so, we can get the P(gas) from this formula:
P(gas) = Height(Hg)
= (103/760) = 0.136 atm

6 0

2 years ago

What would be a simple way to prevent erosion

vladimir1956 [14]

There are many simple ways to prevent erosion. One of the simplest forms of preventing erosion is with vegetation and by establishing root systems that hold the soil together. You can also use geotextiles, fertilizers and also build retainer walls to keep the soil intact and prevent erosion.

8 0

2 years ago