Answer:
A hypothesis is either a suggested explanation for an observable phenomenon, or a reasoned prediction of a possible causal correlation among multiple phenomena. In science, a theory is a tested, well-substantiated, unifying explanation for a set of verified, proven factors.
Explanation:
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Answer:
Paddy
Explanation:
he word paddy is used to describe an artificial pond with raised edges which are used for agriculture.
Answer:
products
Explanation:
In chemistry, chemical reactions is the combination of two or more substances to yield other substances. The substances that react is called REACTANTS while the substances formed after the reaction is called PRODUCTS.
According to this question, a mixture of oxygen and hydrogen is ignited in a test tube as follows:
Hydrogen + Oxygen → Water + Energy
In this reaction, the substances being combined (usually found on the left side of the equation) are hydrogen and oxygen. Hence, oxygen and hydrogen are REACTANTS. Also, the substances produced as a result of the reaction is water (H2O). The PRODUCTS of the reaction is WATER.
<u>Given:</u>
Mass of ice = mass of water = 5.50 kg = 5500 g
Temperature of ice = -20 C
Temperature of water = 75 C
<u>To determine:</u>
Mass of propane required
<u>Explanation:</u>
Heat required to change from ice to water under the specified conditions is:-
q = q(-20 C to 0 C) + q(fusion) + q (0 C to 75 C)
= m*c(ice)*ΔT(ice) + m*ΔHfusion + m*c(water)*ΔT(water)
= 5500[2.10(0-(-20)) + 334 + 4.18(75-0)] = 3792 kJ
The enthalpy change for the combustion of propane is -2220 kJ/mol
Therefore, the number of moles of propane corresponding to the required energy of 3792 kJ = 1 mole * 3792 kJ/2220 kJ = 1.708 moles of propane
Molar mass of propane = 44 g/mol
Mass of propane required = 1.708 moles * 44 g/mol = 75.15 g
Ans: 75.15 grams of propane must be combusted.