All categories

3 years ago

HELP!!!!!!!!!!!! ASAP!!!!!!!!!!!!!!!!!!! CHEMISTRY TEST!!!!!!!!!!!!!! 53 POINTS

Chemistry

1 answer:

lbvjy [14]3 years ago

3 0

Answer:

9.1 KJ

Explanation:

First we must find the number of moles of HBr involved;

number of moles of HBr= mass of HBr/ molar mass of HBr

But molar mass of HBr= 80.91 g/mol

Given mass of HBr from the question= 20.1g

Hence;

Number of moles of HBr= 20.1 g/80.91g

Number of moles of HBr= 0.25 moles of HBr

If 2 moles of HBr has a heat of formation of 72.80KJ

Then 0.25 moles of HBr will have a heat of formation of 0.25× 72.80/2= 9.1 KJ

Therefore; 20.1 g of HBr will have a heat of formation of 9.1 KJ

You might be interested in

Barium sulfate is made by the following reaction.

ipn [44]

Answer:

%age Yield = 96 %

Explanation:

The balance chemical equation for given double replacement reaction is,

Ba(NO₃)₂ + Na₂SO₄ → BaSO₄ + 2 NaNO₃

Step 1: Calculate moles of Ba(NO₃)₂:

Moles = Mass / M.Mass

Moles = 75.1 g / 261.33 g/mol

Moles = 0.2873 moles of Ba(NO₃)₂

Step 2: Find out moles of BaSO₄ formed:

According to balance chemical equation,

1 mole of Ba(NO₃)₂ produced = 1 mole of BaSO₄

So,

0.2873 moles of Ba(NO₃)₂ will produce = X moles of BaSO₄

Solving for X,

X = 0.2873 mol × 1 mol / 1 mol

X = 0.2873 moles of BaSO₄

Step 3: Calculate Theoretical Mass of BaSO₄:

Mass = Moles × M.Mass

Mass = 0.2873 mol × 233.38 g/mol

Mass = 67.07 g of BaSO₄

Step 4: Calculate %age Yield as:

Theoretical Yield = 67.07 g

Actual Yield = 64.4 g

%age Yield = ???

Formula Used:

%age Yield = (Actual Yield ÷ Theoretical Yield) × 100

Putting Values,

%age Yield = (64.4 g ÷ 67.07 g) × 100

%age Yield = 96.01 % ≈ 96 %

6 0

2 years ago

Typhoons are large storms that form over the Pacific Ocean Hurricanes are large storms that form over the Atlantic Ocean. Which

Liula [17]

D. Drop in barometric pressure, warm ocean water, humid air. The low pressure brings in a cool air mass causing collision of two different masses.

My father rode out a typhoon near Okinawa WWII, onboard the battleship USS Missouri BB-63.

Violent pitching, alarms going off for approaching capsize pitch. The captain came on loudspeaker “ don’t worry men, land is near... about a mile straight down”.

8 0

3 years ago

In laboratory experiment, a NOVDEC Student was

Ede4ka [16]

Answer:

i. Molar mass of glucose = 180 g/mol

ii. Amount of glucose = 0.5 mole

Explanation:

The volume of the glucose solution to be prepared = 500 $cm^3$

Molarity of the glucose solution to be prepared = 1 M

i. Molar mass of glucose ( $C_1_2H_6O_6$ ) = (6 × 12) + (12 × 1) + (6 × 16) = 180 g/mol

ii. mole = molarity x volume. Hence;

amount (in moles) of the glucose solution to be prepared

= 1 x 500/1000 = 0.5 mole

3 0

2 years ago

5. Which mineral listed below is commonly known as "fools gold"?

olya-2409 [2.1K]

Answer:

b. pyrite

Explanation:

4 0

2 years ago

What does the number 4 represent in 4nh3

inn [45]

The molecules

the means there is 4 compounds of nh3

6 0

3 years ago