Answer:
Weigh 4.5 grams of sodium hydroxide and add it to the dry volumetric flask of 450 mL followed by small amount of water to dissolve all the NaOH .After this add the water upto tye mark of 450 mL.
Explanation:
Molarity of the solution is the moles of compound in 1 Liter solutions.
Mass of NaOH = x
Molar mass of NaOH = 40 g/mol
Volume of the NaOH solution = 450 mL =- 0.450 L ( 1 ml = 0.450 L)
Molarity of the solution of NaOH = 0.250 M
Solving for x:
x = 4.5 g
Weigh 4.5 grams of sodium hydroxide and add it to the dry volumetric flask of 450 mL followed by small amount of water to dissolve all the NaOH .After this add the water upto tye mark of 450 mL.
Answer:
The activation energy is 7.11 × 10⁴ J/mol.
Explanation:
Let's consider the Arrhenius equation.
where,
k is the rate constant
A is a collision factor
Ea is the activation energy
R is the ideal gas constant
T is the absolute temperature
The plot of ln k vs 1/T is a straight line with lnA as intercept and -Ea/R as slope. Then,
Answer:
B) sand
Explanation:
A) Oil is a wrong choice because it is a liquid not a solid and also if it is oil, it will float over the water surface as a droplets.
B) Sand is the right choice, because sand is a solid and it does not dissolve in water and stabilizes at the bottom.
C) Sugar is a wrong choice, because small amount of sugar will dissolve in water and be a homogeneous solution and does not appear as a particles.
D) Wood ships is also a wrong choice, even it is a solid and does not dissolve in water, but it will float over the water surface.
hydrogen and helium and the most abundant elements in a nebula.
