Answer:
0.00230 = <u>3 significant figures</u>
Explanation:
Significant digits or figures of a given number are the digits or figures that have meaning and contributes to the precision of the given number.
Therefore, <u>0.00230 = 3 significant figures.</u>
Reason: The non-zeros figures and the trailing zero after the decimal are significant. Whereas, all the leading zeros are not considered significant.
Explanation:
1. Thermochemical equation is balance stoichiometric chemical equation written with the phases of the reactants and products in the brackets along with the enthalpy change of the reaction.
The given correct thermochemical reactions are:


2. Phase change affect the value of the enthalpy change of the thermochemical equation. This is because change in phase is accompanied by change in energy. For example:


In both reaction phase of water is changing with change in energy of enthalpy of reaction.
The action was him hitting the ball the reaction was the ball moving after being hit
Most likely the equation yields a new compound XY. This is a synthesis reaction. <span>Synthesis
reaction is a reaction where two or more substances combine to form a new
compound. It is a reaction which releases energy in the form of heat and
light. Therefore, it is an exothermic reaction.</span>