to the proper number of significant figures) to the following? (12.67+19.2)(3.99)/(1.36+ 11.366).
Answer:
The answers to your questions are given below.
Explanation:
Data obtained from the question include:
Mass (M) = 420.0 g
Temperature change (ΔT) = 43.8 °C
Specific heat capacity (C) = 3.52 J/g °C
Heat needed (Q) =...?
The heat needed for the temperature change can be obtained by using the following formula:
Q = MCΔT
Where:
Q is the heat needed measured in joule (J).
M is the mass of substance measured in grams (g)
C is the specific heat capacity of the substance with unit J/g °C.
ΔT is the temperature change measured in degree celsius (°C).
Thus, we can calculate the heat needed to change the temperature as follow:
Q = MCΔT
Q = 420 x 3.52 x 43.8
Q = 64753.92 J
Therefore, the heat needed to cause the temperature change is 64753.92 J
The question is incomplete, here is the complete question:
A chemist measures the amount of bromine liquid produced during an experiment. She finds that 766.g of bromine liquid is produced. Calculate the number of moles of bromine liquid produced. Round your answer to 3 significant digits.
<u>Answer:</u> The amount of liquid bromine produced is 4.79 moles.
<u>Explanation:</u>
To calculate the number of moles, we use the equation:

We are given:
Given mass of liquid bromine = 766. g
Molar mass of liquid bromine,
= 159.8 g/mol
Putting values in above equation, we get:

Hence, the amount of liquid bromine produced is 4.79 moles.
Answer:
7.46 g
Explanation:
From the balanced equation, 2 moles of Mg is required for 2 moles of MgO.
The mole ratio is 1:1
mole = mass/molar mass
mole of 4.50 g Mg = 4.50/24.3 = 0.185 mole
0.185 mole Mg will tiled 0.185 MgO
Hence, theoretical yield of MgO in g
mass = mole x molar mass
0.185 x 40.3 = 7.46 g
Answer:
58.61 grams
Explanation:
Taking The molecular weight of NaCl = 58.44 grams/mole
<u>Determine how many grams of NaCl to prepare the bath solution </u>
first we will calculate the moles of NaCl that is contained in 6L of 170 mM of NaCI solution
= ( 6 * 170 ) / 1000
= 1020 / 1000 = 1.020 moles
next
determine how many grams of NaCl
= moles of NaCl * molar mass of NaCl
= 1.020 * 58.44
= 58.61 grams