Answer:
False
Explanation:
It is important to give exact measurements.
Answer:
1. 0.178 moles ; 2. 8x10²³ atoms ; 3. 7.22x10²³ molecules ; 4. 89.6 g ; 5. 1.34x10²² atoms ; 6. 1.67x10²⁵ molecules
Explanation:
1. Mass / Molar mass = Mol
5g / 28 g/m = 0.178 moles
2. 1 molecule of N₂ has 2 atoms, it is a dyatomic molecule.
4x10²³ x2 = 8x10²³ atoms
3. 1 mol of anything, has 6.02x10²³ particles
6.02x10²³ molecules . 1.2 mol = 7.22x10²³
4. 1 atom of C weighs 12 amu.
4.5x10²⁴ weigh ( 4.5x10²⁴ . 12) = 5.24x10²⁵ amu
1 amu = 1.66054x10⁻²⁴g
5.24x10²⁵ amu = (5.24x10²⁵ . 1.66054x10⁻²⁴) = 89.6 g
5. Molar mass NaCl = 58.45 g/m
1.3 g / 58.45 g/m = 0.0222 moles
1 mol has 6.02x10²³ atoms
0.0222 moles → ( 0.0222 . 6.02x10²³) = 1.34x10²²
6. Density of water is 1 g/mL, so 500 mL are contained in 500 g of water
Molar mass H₂O = 18 g/m
500 g / 18 g/m = 27.8 moles
6.02x10²³ molecules . 27.8 moles = 1.67x10²⁵
Answer:
Pb3O4
Explanation:
According to this question, 3.425g of lead oxide was reduced to form 3.105g of lead in an experiment. Since lead oxide contains both lead (Pb) and oxygen (O) element,
Mass of lead oxide = 3.425g
Mass of lead = 3.105g
Mass of oxygen = (3.425g - 3.105g) = 0.320g
Next, we convert each mass value to mole by dividing by respective molar mass
Pb = 3.105g ÷ 207.2 = 0.0149mol
O = 0.320g ÷ 16 = 0.02mol
Next, we divide each mole value by the smallest (0.0149)
Pb = 0.0149mol ÷ 0.0149mol = 1
O = 0.02mol ÷ 0.0149mol = 1.342
Multiply each ratio value by 3 to get:
Pb = 1 × 3 = 3
O = 1.342 × 3 = 4.026
The whole number ratio, approximately, of Pb and O is 3:4, hence, their empirical formula is Pb3O4.
Answer: Acceleration and velocity
Explanation:
Newton's second law says that when a constant force acts on a massive body, it causes it to accelerate, i.e., to change its velocity, at a constant rate. In the simplest case, a force applied to an object at rest causes it to accelerate in the direction of the force.
Answer:
Space exploration thus supports innovation and economic prosperity by stimulating advances in science and technology, as well as motivating the global scientific and technological workforce, thus enlarging the sphere of human economic activity.
