Answer:
B
Explanation:
Because the sharpener is attached to an electrical outlet
Answer:
4.81×10¹⁰ atoms.
Explanation:
We'll begin by converting 3.2 pg to Ca to grams (g). This can be obtained as follow:
1 pg = 1×10¯¹² g
Therefore,
3.2 pg = 3.2 pg × 1×10¯¹² g / 1 pg
3.2 pg = 3.2×10¯¹² g
Therefore, 3.2 pg is equivalent to 3.2×10¯¹² g
Next, we shall determine the number of mole in 3.2×10¯¹² g of Ca. This can be obtained as follow:
Mass of Ca = 3.2×10¯¹² g
Molar mass of Ca = 40.08 g/mol
Mole of ca=.?
Mole = mass /molar mass
Mole of Ca = 3.2×10¯¹² / 40.08
Mole of Ca = 7.98×10¯¹⁴ mole.
Finally, we shall determine the number of atoms present in 7.98×10¯¹⁴ mole of Ca. This can be obtained as illustrated below:
From Avogadro's hypothesis,
1 mole of Ca contains 6.02×10²³ atoms.
Therefore, 7.98×10¯¹⁴ mole of Ca will contain = 7.98×10¯¹⁴ × 6.02×10²³ = 4.81×10¹⁰ atoms.
Therefore, 3.2 pg of Ca contains 4.81×10¹⁰ atoms.
Answer:
Molecular formula = P₄O₁₀
Explanation:
Given data:
Empirical formula = P₂O₅
Gram molecular mass = 284 g/mol
Molecular formula = ?
Solution:
Molecular formula = n (empirical formula)
n = molar mass of compound / empirical formula mass
Empirical formula mass = 2 ×31 + 5× 16 = 142
n = 284 / 142
n = 2
Molecular formula = n (empirical formula)
Molecular formula =2 (P₂O₅)
Molecular formula = P₄O₁₀
An enzyme can affect a chemical reaction by bringing the reactant closer together - chemical bonds may be weakened, and reactions will happen faster than without a catalyst. The energy can also be lowered, which means reactions will proceed at a lower temperature, light presence, etc.