Explanation:
When the forces acting on an object are balanced , there is no change in the object's motion.
A force acting on a resting object can cause the object to move.
On Earth, gravity pulls all objects toward the ground.
When a force acts in the opposite direction of another force, the forces counteract each other.
More than one force acting on a falling object can reduce its downward acceleration
Air resistance is caused by molecules of air pushing against a moving object
Answer:
CH₄
Explanation:
To determine the empirical formula of the hydrocarbon, we need to follow a series of steps.
Step 1: Determine the mass of the compound
The mass of the compound is equal to the sum of the masses of the elements that form it.
m(CxHy) = mC + mH = 7.48 g + 2.52 g = 10.00 g
Step 2: Calculate the percent by mass of each element
%C = mC / mCxHy × 100% = 7.48 g / 10.00 g × 100% = 74.8%
%H = mH / mCxHy × 100% = 2.52 g / 10.00 g × 100% = 25.2%
Step 3: Divide each percentage by the atomic mass of the element
C: 74.8/12.01 = 6.23
H: 25.2/1.01 = 24.95
Step 4: Divide both numbers by the smallest one, i.e. 6.23
C: 6.23/6.23 = 1
H: 24.95/6.23 ≈ 4
The empirical formula of the hydrocarbon is CH₄.
Answer: 1.99 x 10²² molecules H2
Explanation:First we will solve for the moles of H2 using Ideal gas law PV= nRT then derive for moles ( n ).
At STP, pressure is equal to 1 atm and Temperature is 273 K.
Convert volume in mL to L:
750 mL x 1 L / 1000 mL
= 0.75 mL
n = PV/ RT
= 1 atm ( 0.75 L ) / 0.0821 L.atm/ mole.K ( 273 K)
= 3.3x10-² moles H2
Convert moles of H2 to atoms using Avogadro's Number.
3.3x10-² moles H2/ 6.022x10²³ atoms H2 / 1 mole H2
= 1.99x10²² atoms H2
Molecular weight of (NH4)2 CO3 = 96 gm. 96 gm (NH4)2CO3 = 1 mol of (NH4)2CO3 = 2 moles of NH4.
Therefore 1.3 gm of (NH4)2CO3 = 1.3x2/ 96 = 0.027 moles.
