Chemical changes:
burning wood
digesting food
mixing acid and base
Physical changes:
breaking a bottle
melting an ice cube
crumbling a sheet of paper
Answer: H2O (water)
Explanation:
The answer choices for this question are:
A) H2O
B) N2
C) SO2
D) NO3
E) Cl2
The solution of the problem is:
1) Data:
<span> density, d = 1.4975 g/liter
volume, V = 8.64 liter
pressure, p = 2.384 atm
temperature, T = 349.6 K
2) Formulas:
d = m/V => m = d*V
n = m / molar mass => molar mass = m / n
pV = nRT => n = pV / RT
3) Solution
n = pV / RT = 2.384 atm * 8.64 liter / (0.0821 atm*liter/K*mol * 349.6K)
n = 0.7176 moles
</span>m = dV = 1.4975 g/ liter * <span>8.64 liter = 12.9384 g
molar mass = m / n = 12.9384 g / 0.7176 moles = 18.03 g/mol
That molar mass corresponds to the molar mass of water, therefore the gas is H2O (water vapor).</span>
Answer: 0.4M
Explanation:
Given that,
Amount of moles of NaOH (n) = ?
Mass of NaOH in grams = 40.0g
For molar mass of NaOH, use the atomic masses: Na = 23g; O = 16g; H = 1g
NaOH = (23g + 16g + 1g)
= 40g/mol
Since, n = mass in grams / molar mass
n = 40.0g / 40.0g/mol
n = 1 mole
Volume of NaOH solution (v) = 2.5 L
Concentration of NaOH solution (c) = ?
Since concentration (c) is obtained by dividing the amount of solute dissolved by the volume of solvent, hence
c = n / v
c = 1 mole / 2.5 L
c = 0.4 mol/L (Concentration in mol/L is the same as Molarity, M)
Thus, the concentration of a solution of a 40.0 g of NaOH in 2.5 L of solution is 0.4 mol/L or 0.4M
Answer: A) Na+ and O2-
Explanation:
To know the electronic configuration, one has to determine the numbers of electrons present in each atom.
Na+ means a sodium atom that has lost one valence electron. A Sodium atom initially has 11 electrons, but having lost an electron making it 10 electrons remaining with electron configuration of 1s2 2s2 2p6.
O2- means oxygen atom that has gained two valence electrons. An oxygen atom initially has 8 electrons, having gained two electrons makes it 10 electrons with electron configuration of 1s2 2s2 2p6. same as Na+
The purpose of gaining or losing electrons is to attain a stable duplet or octet structure.
Answer:
The reactions free energy 
Explanation:
From the question we are told that
The pressure of (NO) is 
The pressure of (Cl) gas is 
The pressure of nitrosly chloride (NOCl) is 
The reaction is
⇆ 
From the reaction we can mathematically evaluate the 
(Standard state free energy ) as
The Standard state free energy for NO is constant with a value
The Standard state free energy for 
is constant with a value
The Standard state free energy for 
is constant with a value
Now substituting this into the equation
The pressure constant is evaluated as
Substituting values
The free energy for this reaction is evaluated as
Where R is gas constant with a value of 
T is temperature in K with a given value of 
Substituting value
![\Delta G = -43 *10^{3} + 8.314 *298 * ln [0.0765]](https://tex.z-dn.net/?f=%5CDelta%20%20G%20%20%3D%20-43%20%2A10%5E%7B3%7D%20%2B%208.314%20%2A298%20%2A%20ln%20%5B0.0765%5D)
