<h3>Answer:</h3>
Excess Reagent = NBr₃
<h3>Solution:</h3>
The Balance Chemical Equation for the reaction of NBr₃ and NaOH is as follow,
2 NBr₃ + 3 NaOH → N₂ + 3 NaBr + 3 HBrO
Calculating the Limiting Reagent,
According to Balance equation,
2 moles NBr₃ reacts with = 3 moles of NaOH
So,
40 moles of NBr₃ will react with = X moles of NaOH
Solving for X,
X = (40 mol × 3 mol) ÷ 2 mol
X = 60 mol of NaOH
It means 40 moles of NBr₃ requires 60 moles of NaOH, while we are provided with 48 moles of NaOH which is Limited. Therefore, NaOH is the limiting reagent and will control the yield of products. And NBr₃ is in excess as some of it is left due to complete consumption of NaOH.
Answer : The pH value of an acid is below 7.
Explanation :
pH : It is defined as the negative logarithm of hydrogen ion or hydronium ion concentration.
Mathematically,
![pH=-\log [H^+]](https://tex.z-dn.net/?f=pH%3D-%5Clog%20%5BH%5E%2B%5D)
When the pH less than 7 then the solution is acidic and the concentration of hydrogen ion is greater than hydroxide ion.
When the pH more than 7 then the solution is basic and the concentration of hydrogen ion is less than hydroxide ion.
When the pH is equal to 7 then the solution is neutral and the concentration of hydrogen ion is equal to the hydroxide ion.
Hence, the pH value of an acid is below 7.
<h3>
Answer:</h3>
0.012 dekameters (dkm)
<h3>
Explanation:</h3>
<u>We are given;</u>
Required to identify the measurements that is not equivalent to 120 cm.
- Centimeters are units that are used to measure length together with other units such as kilometers(km), meters (m), millimeters (mm), dekameters (dkm), etc.
- These units can be inter-converted to one another using suitable conversion factors.
- To do this, we are going to have a table showing the suitable conversion factor from one unit to another.
Kilometer (km)
10
Decimeter (Dm)
10
Hectometer (Hm)\
10
Meter (m)
10
Dekameter (dkm)
10
Centimeter (cm)
10
Millimeter (mm)
Therefore;
To convert cm to km
Conversion factor is 10^5 cm/km
Thus;
120 cm = 120 cm ÷ 10^5 cm/km
= 0.0012 km
To convert cm to dkm
Conversion factor is 10 cm/dkm
Therefore,
120 cm = 120 cm ÷ 10 cm/dkm
= 12 dkm
To convert cm to m
The suitable conversion factor is 10^2 cm/m
Thus,
120 cm = 120 cm ÷ 10^2 cm/m
= 1.2 m
To convert cm to mm
Suitable conversion factor is 10 mm/cm
Therefore;
120 cm = 120 cm × 10 mm/cm
= 1200 mm
Therefore, the measurement that is not equal to 120 cm is 0.012 dkm
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:
chemical change
Explanation:
chemical change requires energy in the form of heat or electricity.
