Answer:
0.129g MgCl2
Explanation:
For this we need to understand the concept of molarity.
Molarity is number of moles of solute/litres of solution
M=n/L
Here we are given molarity of 0.054M and volume of 25ml. we just plug this in formula to find moles of MgCl2
0.054=x/(25/1000) (we divided 25 by 1000 to convert it to litres of solution)
x=0.00135 moles of MgCl2 (we are not done yet the question asks for grams so to convert to grams we multiply by molar mass of MgCl2.)
0.00135molesMgCl2 x 95.211g MgCl2/1molMgCl2
= 0.129g MgCl2
The answer will be, so3 since s only need two electrons to complete its octet
Answer: 8556 mm, or 855.6 cm (8560 mm to 3 sig figs)
Explanation: Convert mm to cm by dividing by 10 (1cm/10mm)
Find the area of the foil face in cm^2 (30cm*0.2020cm) = 0.606 cm^2
Calculate the volume occupied by 1.40 kg of foil in cm^3. 1.40kg = 1400g
1.400g/(2.7 g/cm^3) = 518.5 cm^3 for 1.40 kg Au
Volume = Area (of the face) * Length
We want Length:
Length = Volume/Area
L = (518.5 cm^3/0.606 cm^2)
L = 855.6 cm (8556 mm) Round to 3 sig figs (856 cm and 8560 mm)
First, we need to get n1 (no.of moles of water ): when
mass of water = 0.0203 g and the volume = 1.39 L
∴ n1 = mass / molar mass of water
= 0.0203g / 18 g/mol
= 0.00113 moles
then we need to get n2 (no of moles of water) after the mass has changed:
when the mass of water = 0.146 g
n2 = mass / molar mass
= 0.146g / 18 g/ mol
= 0.008 moles
so by using the ideal gas formula and when the volume is not changed:
So, P1/n1 = P2/n2
when we have P1 = 1.02 atm
and n1= 0.00113 moles
and n2 = 0.008 moles
so we solve for P2 and get the pressure
∴P2 = P1*n2 / n1
=1.02 atm *0.008 moles / 0.00113 moles
= 7.22 atm
∴the new pressure will be 7.22 atm
Answer is: 5,170 J of heat is absorbed by the reaction.
ΔT= 28.50°C - 27.45°C = 1.05°C; temperature change.
m = 1400 g; mass of substance.
cp= 3.52 J/g·°C, specific heat capacity of the substance.
Q = m(granite) · ΔT(granite) · cp(granite).
Q = 1400 g · 1.05°C · 3.52 J/g·°C.
Q = 5,170 J; amount of energy gained.