Answer:
Explanation:
During titration indicators are often used to identify chemical changes between reacting species.
For colorless solutions in which no noticeable changes can easily be seen, indicators are the best bet. Most titration processes involves a combination of acids and bases to an end point.
Indicators are substances whose color changes to signal the end of an acid-base reaction. Examples are methyl orange, methyl red, phenolphthalein, litmus, cresol red, cresol green, alizarin R3, bromothymol blue and congo red.
Most of these indicators have various colors when chemical changes occur.
Also, there are heat changes that accompanies most of these reactions. These are also indicators of chemical changes.
Answer: K and Mg
Explanation:
The first one refers to the atomic radius and increases going down and to the left on the periodic table. K is in between Rb and Na.
The answer is d. hope it helps
The volume of the gas at STP = 35.01 L
<h3>Further explanation</h3>
Conditions at T 0 ° C and P 1 atm are stated by STP (Standard Temperature and Pressure).
In general, the gas equation can be written

where
P = pressure, atm
V = volume, liter
n = number of moles
R = gas constant = 0.08206 L.atm / mol K
T = temperature, Kelvin
V=17.4 L
T = 23 + 273 = 296 K
P = 2.18 atm

The volume of the gas occupy at STP :

Answer:
27.98g/mol
Explanation:
Using ideal gas law equation;
PV = nRT
Where;
P = pressure (atm)
V = volume (L)
T = temperature (K)
n = number of moles (mol)
R = gas law constant (0.0821 Latm/molK)
According to the information given:
V = 2.5L
P = 1.4 atm
T = 282K
n = ?
Using PV = nRT
n = PV/RT
n = 1.4 × 2.5/0.0821 × 282
n = 3.5/23.1522
n = 0.151mol
Using the formula to calculate molar mass of the elemental gas:
mole = mass/molar mass
Molar mass = mass/mole
Molar mass = 4.23g ÷ 0.151mol
Molar mass = 27.98g/mol