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3 years ago

In the winter , people often buy large bags of rock salt to sprinkle on their walkways . Why do people do this?

1 answer:

6 0

The salt causes the water to freeze at a lower temperature. When a solute, aka salt, is introduced to the system, the freezing point is lowered. This makes the water freeze at a lower temperature.

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PORFA AYUDAA !!!

matrenka [14]

Explanation:

The problem here is to find the atomic number of each of the element given.

Sum the powers of the configuration.

a- 1s² 2s² 2p⁶ 3s² 3p⁶ 4s¹

Atomic number is = 2 + 2 + 6 + 2 + 6 + 1 = 19

b- 1s² 2s² 2p⁶ 3s² 3p⁴

Atomic number = 2 + 2 + 6 + 2 + 4 = 16

c- 1s¹

Atomic number = 1

6 0

3 years ago

Please help asap! I need help with this, C.E.R for chemistry

inn [45]

Answer:

no they don't

Explanation:

please go check my image upwards .

5 0

3 years ago

Round 0.0645 g to 2 significant figures

Hoochie [10]

The number of significant figures within a number are the amount digits that are required to specify a number to a certain degree of accuracy. In the number, 0.0645 g, the 6 is the most significant figure and 4 is the second most significant figure. Therefore, rounding to two significant figures yields 0.064g.

5 0

3 years ago

Consider the following reaction: 3Fe(s) + 4H₂O(g) ➞ Fe₃O₄(s) + 4H₂(g). To answer the following question: "How many moles of hot

Elodia [21]

Answer: 2

Explanation:

To calculate the moles :

$\text{Moles of solute}=\frac{\text{given mass}}{\text{Molar Mass}}$

$\text{Moles of} Fe_3O_4=\frac{275g}{233.5g/mol}=1.18moles$

$3Fe(s)+4H_2O(g)\rightarrow Fe_3O_4(s)+4H_2(g)$

According to stoichiometry :

1 mole of $Fe_3O_4$ are produced by = 4 moles of $H_2O$

Thus 1.18 moles of $Fe_3O_4$ will be produced by= $\frac{4}{1}\times 1.18=4.72moles$ of $H_2O$

Mass of $H_2O=moles\times {\text {Molar mass}}=4.72moles\times 18g/mol=85.0g$

Thus 85.0 g of $H_2O$ will be required and 2 steps are required to get the answer.

6 0

3 years ago

A mixture of carbon dioxide and helium gases is maintained in a 7.91 L flask at a pressure of 1.42 atm and a temperature of 33 °

Crank

Answer:

The gas mixture contains 1.038 grams of helium

Explanation:

Step 1: Data given

Volume of the flask = 7.91 L

Total Pressure = 1.42 atm

Temperature = 33 °C

Mass of CO2 = 8.25 grams

Molar mass of CO2 = 44.01 g/mol

Molar mass of He = 4 g/mol

Step 2: Calculate total number moles of gas

p*V = n*R*T

⇒ p = the pressure = 1.42 atm

⇒ V = the volume = 7.91 L

⇒ n= the number of moles = TO BE DETERMINED

⇒ R = the gas constant = 0.08206 L* atm/K*mol

⇒ T = the temperature = 33 °C = 306 Kelvin

n = (p*V)/(R*T)

n = (1.42*7.91)/(0.08206 * 306)

n = 0.447 moles

Step 3: Calculate moles of CO2

Moles CO2 = mass CO2 / Molar mass CO2

Moles CO2 = 8.25 grams / 44.01 g/mol

Moles CO2 = 0.1875 moles

Step 4: Calculate moles of Helium

Moles Helium = total moles of gas - moles of CO2

Moles Helium = 0.447 - 0.1875 = 0.2595 moles of helium

Step 5: Calculate mass of helium

Mass of helium = moles of helium * molar mass of helium

Mass of helium = 0.2595 moles * 4 g/mol

Mass of helium = 1.038 grams

The gas mixture contains 1.038 grams of helium

8 0

3 years ago