Hey There!:
The density is the quotient between the mass of a material and the volume occupied by it, The density can be expressed for a substance or for a mixture of substances. For example, water density in ambient conditions is equal to 1.00 g/cm3, which means that in 1 cm³ or 1 mL, there are 1.0 g of water. Therefore:
D = m / V
D = 20 g / 5 mL
D = 4,0 g/mL
hope that helps!
To find the molarity of the compound, simply determine the molar mass of MgCl2 and then convert 50 g to moles using the molar mass of the compound. Then convert 150 ml to L = 0.15 L
Then divide the moles amount by the volume in L.
The two samples don’t contain different atoms so it will be false
Answer: 36.6°C
Explanation:
Given that,
initial pressure of helium (P1) = 1.20 atm
Initial temperature (T1) = 22.0°C
Final temperature (T2) = ?
Final pressure of helium (P2) = 2.00 atm
Since pressure and temperature are given while volume is constant, apply the formula for pressure's law
P1/T1= P2/T2
1.20 atm / 22.0°C = 2.00 atm / T2
Cross multiply
1.20 atm•T2= 2.00 atm•22°C
1.20 atm•T2= 44 atm•°C
Divide both sides by 1.20 atm
1.20 atm•T2/1.20 atm = 44 atm•°C/1.20 atm
T2 = 36.6°C
When NH3 is dissolved in water, it dissociates partially producing NH4+ ions and OH- ions. It has an equation:
NH3 + H2O → NH4+ + OH-
<span>We use the Kb expression to determine the [OH-] concentration,
</span>
<span>Kb = [NH4+] [OH-] /* [NH3] </span>
We can write NH4+ as OH- since they are of equal ratio.
<span>(1.76*10^-5) = [OH-]² / 0.188
</span><span>[OH-]² = 3.3088*10^-6 </span>
<span>[OH-] = 1.819*10^-3 </span>
We calculate for H+ concentration as follows:
<span>[H+] [OH-] = 10^-14 </span>
<span>[H+] = 10^-14 / [OH-] </span>
<span>[H+] = 10^-14 / (1.819*10^-3) </span>
<span>[H+] = 5.50*10^-12 </span>
<span>pH = -log [H+] </span>
<span>pH = -log (5.5*10^-12) </span>
<span>pH = 11.26</span>
