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3 years ago

A salt crystal has a mass 0.14mg,How many NaCl formula units does it contain?

1 answer:

4 0

To determine the number of formula units in a sample of a compound you need to divide the number of grams by the formula mass. The formula mass of NaCl is 23 g/mol + 35.5 g/mol = 58.5 g/mol, and the number of grams of the sample is 0.14 mg * 1 g/ 1000 mg = 0.00014 g. Then the answer is 0.00014 g / 58.5 g = 2.30 * 10^ -6, which rounded to two significant figures is 2.4 * 10^ -6. So the answer is 2.4 * 10^-6 or 0.0000024

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What is the scientific method describes as nonlinear

Phoenix [80]

Scientists often repeat one or more steps several times.

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3 years ago

A sample of He gas (3.0 L) at 5.6 atm and 25°C was combined with 4.5 L of Ne gas at 3.6 atm and 25°C at constant temperature in

In-s [12.5K]

Answer:

3.6667

Explanation:

For helium gas:

Using Boyle's law

${P_1}\times {V_1}={P_2}\times {V_2}$

Given ,

V₁ = 3.0 L

V₂ = 9.0 L

P₁ = 5.6 atm

P₂ = ?

Using above equation as:

${P_1}\times {V_1}={P_2}\times {V_2}$

${5.6}\times {3.0}={P_2}\times {9.0} atm$

${P_2}=\frac {{5.6}\times {3.0}}{9.0} atm$

${P_1}=1.8667\ atm$

The pressure exerted by the helium gas in 9.0 L flask is 1.8667 atm

For Neon gas:

Using Boyle's law

${P_1}\times {V_1}={P_2}\times {V_2}$

Given ,

V₁ = 4.5 L

V₂ = 9.0 L

P₁ = 3.6 atm

P₂ = ?

Using above equation as:

${P_1}\times {V_1}={P_2}\times {V_2}$

${3.6}\times {4.5}={P_2}\times {9.0} atm$

${P_2}=\frac {{3.6}\times {4.5}}{9.0} atm$

${P_1}=1.8\ atm$

The pressure exerted by the neon gas in 9.0 L flask is 1.8 atm

Thus total pressure = 1.8667 + 1.8 atm = 3.6667 atm.

6 0

3 years ago

(e)

mars1129 [50]

Answer:36g

Explanation:6.8:3.6=68:x

x=68*3.6/6.8=36

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3 years ago

Can any one please help me to answers this question i don't get it. thank in advance.

alex41 [277]

First, lets balance the reaction equation:
4Fe + 3O₂ → 2Fe₂O₃
It is visible form the equation that 4 moles of Fe require 3 moles of O₂
Molar ratio Fe/O₂ = 4/3 = 1.33
Molar ratio O₂/Fe = 3/4 = 0.75
Now, we check the molar ratios present:
Fe/O₂ = 6.8/8.9 = 0.76
O₂/Fe = 1.31

Thus, Iron is the limiting reactant because its ratio is not being fulfilled while the ratio of O₂ is surpassed.

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