Uranium has an atomic number of 92. How many neutrons does U-238 have?

____________ enables you to ride a bike without skidding and falling.

Marina86 [1]

Sliding or rolling friction

4 0

2 years ago

24g of methane were burned in an excess of air. What mass of water would be produced in the reaction assuming complete combustio

expeople1 [14]

Answer:

54g of water

Explanation:

Based on the reaction, 1 mole of methane produce 2 moles of water.

To solve this question we must find the molar mass of methane in order to find the moles of methane added. With the moles of methane and the chemical equation we can find the moles of water produced and its mass:

Molar mass CH₄:

1C = 12g/mol*1

4H = 1g/mol*4

12g/mol + 4g/mol = 16g/mol

Moles methane:

24g CH₄ * (1mol / 16g) = 1.5 moles methane

Moles water:

1.5moles CH₄ * (2mol H₂O / 1mol CH₄) = 3.0moles H₂O

Molar mass water:

2H = 1g/mol*2

1O = 16g/mol*1

2g/mol + 16g/mol = 18g/mol

Mass water:

3.0moles H₂O * (18g / mol) =

<h3>54g of water</h3>

8 0

3 years ago

When 10.0 grams of sulfur reacts with fluorine gas at a pressure of 2.69 atmosphere in a 5.00 L container at 0.00 degrees Celsiu

Gwar [14]

Answer:

74.1%

Explanation:

Based on the reaction:

S₈ + 16F₂ → 8SF₄

1 mole of sulfur reacts with 16 moles of F₂ to produce 8 moles of SF₄

To solve this question we must find the moles of each reactant in order to find the moles of SF₄. Thus, we can find the theoretical mass produced. Percent yield is:

Percent yield = Actual yield (25.0g) / Theoretical yield * 100

Moles S₈: 256.52g/mol

10.0g * (1mol / 256.52g) = 0.0390 moles

Moles F₂:

PV = nRT

PV/RT = n

Where P is pressure in atm, V is volume in liters, R is gas constant and T is absolute temperature (0°C = 273.15K)

2.69atm*5.00L / 0.082atmL/molK*273.15K = n

0.600 moles = n

For a complete reaction of 0.600 moles F₂ are required:

0.600mol F₂ * (1mol S₈ / 8 mol F₂) = 0.075 moles S₈

As there are just 0.0390 moles, S₈ is limiting reactant.

The theoretical moles and mass of SF₄ -Molar mass: 108.07g/mol- is:

0.0390 moles S₈ * (8mol SF₄ / 1mol S₈) = 0.312 moles SF₄ * (108.07g) =

33.7g

Percent yield = 25.0g / 33.7g * 100

= 74.1%

6 0

2 years ago

Determine the mass in grams of sucrose that must be added to 26 g of water to make a 1.15 m solution. Enter your answer to 2 dec

True [87]

Answer:

10.23 grams of sucrose should be added.

Explanation:

1.15 m means molality (moles of solute in 1kg of solvent)

1.15 moles of sucrose are contained in 1 kg of solvent (1000 g)

Let's determine the moles in our mass of solvent.

Firstly we convert the g to kg → 26 g . 1kg/1000g = 0.026 kg

m . mass (kg) = 1.15 mol/kg . 0.026kg → 0.0299 moles.

Finally we convert the moles to mass (mol . molar mass)

0.0299 mol . 342.3 g/mol = 10.23 g

4 0

3 years ago

Read 2 more answers

In the lab you find four bags; each contains 5.00 g of a different gas at STP. The gases are O2, CH4, CO2, and He. Which bag has

hichkok12 [17]

Answer:

lesser the molar mass of the gas higher the no. of moles included in a certain mass sample. ie at STP more volume is required for the gas having less molar mass.

He has the smallest molar mass.

Therefore bag of He is the biggest.

4 0

3 years ago