"A machine can decrease either the input force or the input distance needed to do a given amount of work" is the best statement that describes why a machine is useful.
Answer: Option D
<u>Explanation
:</u>
A machine is simply defined as a device that helps humans, helping them to transfer the required amount of force to compete any task, changing the direction of motion, increasing the magnitude of force to complete any task, reduce the time or distance needed to cover while performing any task.
Machines can be simple mechanical device or a combination of multiple mechanical or technical devices to reduce the amount of input force or increase the output.
<span>Quantity can always be used the same way as moles when interpreting balanced chemical equations.</span>
Answer:
is a substance which donates an H^+ or a proton
Answer: 15.1 grams
Given reaction:
Na2CO3 + Ca(OH)2 → 2NaOH + CaCO3
Mass of Na2CO3 = 20.0 g
Molar mass of Na2CO3 = 105.985 g/mol
# moles of Na2CO3 = 20/105.985 = 0.1887 moles
Based on the reaction stoichiometry: 1 mole of Na2CO3 produces 2 moles of NaOH
# moles of NaOH produced = 0.1887*2 = 0.3774 moles
Molar mass of NaOH = 22.989 + 15.999 + 1.008 = 39.996 g/mol
Mass of NaOH produced = 0.3774*39.996 = 15.09 grams
Explanation:
Answer:
The pH is 1.08, being an acid pH
Explanation:
pH is a parameter used to measure the degree of acidity or alkalinity of a substance. The pH scale ranges from 0 to 14. Values less than 7 indicate the acidity range and those greater than 7 indicate alkalinity or basicity. Value 7 is considered neutral. Mathematically, pH is the negative logarithm of the molar concentration of hydrogen or proton ions (H⁺) or hydronium ions (H₃O⁺).
pH= - log [H⁺]= - log [H₃O⁺]
A strong acid is an acid that completely dissociates into hydrogen ions and anions in solution. This implies that the initial concentration of acid is equal to the final concentration of H₃O⁺. This occurs with acid HCl.
So, pH is calculated as:
pH= - log (0.083)
pH= 1.08
<u><em>The pH is 1.08, being an acid pH</em></u>
