1. A 2.25 g sample of scandium (Sc) metal is reacted with excess hydrochloric acid to produce 2.41 L of hydrogen gas at 100°C and 0.950 atm. Determine the formula of the ""scandium chloride"" produced in the reaction.

The formula of scandium chloride is ScCl3

Explanation:

Step 1: Data given

Mass of scandium = 2.25 grams

Volume of hydrogen gas produce = 2.41 L

Temperature = 100 °C = 373 K

Pressure = 0.950 atm

Step 2: Calculatem oles of scandium

Moles Sc = mass Sc / molar mass Sc

Moles Sc = 2.25 grams / 44.955 g/mol

Moles Sc = 0.050 moles

Step 3: Calculate moles hydrogen gas

p*V = n*R*T

⇒with p = the pressure of H2 gas = 0.950 atm

⇒with V = the volume of H2 gas = 2.41 L

⇒with n = the number of moles H2 gas = TO BE DETERMINED

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

⇒with T = the temperature 373 K

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

n = (0.950 * 2.41)/(0.08206*373)

n = 0.0748 moles

Step 4: Calculate mole ratio

n(Sc)/n(H2) = 0.05 moles / 0.0748 moles

n(Sc)/ n(H2) = 2/3

This means for 2 moles Sc we'll have 3 moles H2

2Sc + HCl → ScCl + 3H2

Since we have 6x H on the right side, we have to multiply HCl on the left side by 6. To balance the amount of H.

2Sc + 6HCl → ScCl + 3H2

Since we have 2x Sc on the left side, and 1x Sc (in ScCl) on the right (in ScCl) we have to multiply ScCl on the right side by 2

2Sc + 6HCl → 2ScCl + 3H2

This means We have 3x Cl in the scandium chloride (ScCl3)

The formula of scandium chloride is ScCl3

the answer is false because not all countries have geysers under their crust. for example, iceland uses geothermal energy because it is available every in their country.  

linda: 3 ; laura: 15

step-by-step explanation:

note that linda + laura's age is 18, and that linda is 12 years younger than her sister.

let "linda" = x , "laura" = y:

x + y = 18

x = y - 12

first, plug in y - 12 for x in the first equation:

(y - 12) + y = 18

simplify.

2y - 12 = 18

isolate the variable (y). note the equal sign, what you do to one side, you do to the other. do the opposite of pemdas. first add, then divide.

2y - 12 (+12) = 18 (+12)

2y = 18 + 12

2y = 30

(2y)/2 = (30)/2

y = 30/2

y = 15

next, plug in 15 for y in the second equation (the other equation would work too).

x = y - 12

x = (15) - 12

x = 3

linda's age is 3, laura's age is 15.

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